CVE-2026-121994 (GCVE-0-2026-121994)
Vulnerability from cvelistv5 – Published: 2026-11-05 16:08 – Updated: 2026-11-06 19:55
VLAI
EPSS
VEX
Title
Gdb: gdb: stack buffer overflow in fetch_register_using_p via unchecked p-reply length
Summary
A stack buffer overflow in the GDB client's remote protocol handler allows an attacker-controlled debug target to execute arbitrary code in the GDB process. The vulnerability exists in fetch_register_using_p, which decodes a stub's register reply into an alloca-sized buffer without bounding writes by the register width.
Severity
8.8 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-11-05 00:00 UTC
CWE
- CWE-121 - Stack-based Buffer Overflow
Assigner
redhat
CNA
References
2 references
| URL | Tags |
|---|---|
| https://access.redhat.com/security/cve/CVE-2026-121994 | vdb-entryx_refsource_REDHAT |
| https://bugzilla.redhat.com/show_bug.cgi?id=2565676 | issue-trackingx_refsource_REDHAT |
Impacted products
6 products
| Vendor | Product | Version | |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 |
cpe:/a:redhat:enterprise_linux:10
|
|
| Red Hat | Red Hat Enterprise Linux 6 |
cpe:/o:redhat:rhel_els:6
|
|
| Red Hat | Red Hat Enterprise Linux 7 |
cpe:/o:redhat:rhel_els:7
|
|
| Red Hat | Red Hat Enterprise Linux 8 |
cpe:/a:redhat:enterprise_linux:8
|
|
| Red Hat | Red Hat Enterprise Linux 9 |
cpe:/a:redhat:enterprise_linux:9
|
|
| Red Hat | Red Hat Hardened Images |
cpe:/a:redhat:hummingbird:1
|
Date Public
2026-11-05 14:25
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-121994",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-11-05T00:00:00+00:00",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-11-06T04:56:37.588Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:10"
],
"defaultStatus": "unaffected",
"packageName": "crash",
"product": "Red Hat Enterprise Linux 10",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:10"
],
"defaultStatus": "affected",
"packageName": "gdb",
"product": "Red Hat Enterprise Linux 10",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:rhel_els:6"
],
"defaultStatus": "affected",
"packageName": "gdb",
"product": "Red Hat Enterprise Linux 6",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:rhel_els:7"
],
"defaultStatus": "affected",
"packageName": "gdb",
"product": "Red Hat Enterprise Linux 7",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:8"
],
"defaultStatus": "unaffected",
"packageName": "crash",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:8"
],
"defaultStatus": "affected",
"packageName": "gcc-toolset-14-gdb",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:8"
],
"defaultStatus": "affected",
"packageName": "gcc-toolset-15-gdb",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:8"
],
"defaultStatus": "affected",
"packageName": "gdb",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:9"
],
"defaultStatus": "unaffected",
"packageName": "crash",
"product": "Red Hat Enterprise Linux 9",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:9"
],
"defaultStatus": "affected",
"packageName": "gdb",
"product": "Red Hat Enterprise Linux 9",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:hummingbird:1"
],
"defaultStatus": "affected",
"packageName": "gdb",
"product": "Red Hat Hardened Images",
"vendor": "Red Hat"
}
],
"credits": [
{
"lang": "en",
"value": "Red Hat would like to thank Pulkit Singh Singaria for reporting this issue."
}
],
"datePublic": "2026-11-05T14:25:22.606Z",
"descriptions": [
{
"lang": "en",
"value": "A stack buffer overflow in the GDB client\u0027s remote protocol handler allows an attacker-controlled debug target to execute arbitrary code in the GDB process. The vulnerability exists in fetch_register_using_p, which decodes a stub\u0027s register reply into an alloca-sized buffer without bounding writes by the register width."
}
],
"metrics": [
{
"other": {
"content": {
"namespace": "https://access.redhat.com/security/updates/classification/",
"value": "Important"
},
"type": "Red Hat severity rating"
}
},
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 8.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-121",
"description": "Stack-based Buffer Overflow",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-11-06T19:55:31.918Z",
"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
"shortName": "redhat"
},
"references": [
{
"tags": [
"vdb-entry",
"x_refsource_REDHAT"
],
"url": "https://access.redhat.com/security/cve/CVE-2026-121994"
},
{
"name": "RHBZ#2565676",
"tags": [
"issue-tracking",
"x_refsource_REDHAT"
],
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2565676"
}
],
"timeline": [
{
"lang": "en",
"time": "2026-10-21T08:41:10.000Z",
"value": "Reported to Red Hat."
},
{
"lang": "en",
"time": "2026-11-05T14:25:22.606Z",
"value": "Made public."
}
],
"title": "Gdb: gdb: stack buffer overflow in fetch_register_using_p via unchecked p-reply length",
"workarounds": [
{
"lang": "en",
"value": "There is no mitigation for this vulnerability. Users should only connect GDB to trusted debug targets.\n\n--- CME Mitigation Guidance (2026-11-06) ---\nDisclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure.\n\nThe highest-value action is to enforce bounds checking against register size when decoding remote serial protocol register replies in the GDB client remote protocol handler: upgrade to the corresponding fixed Red Hat builds, which bounds RSP register reply decoding to the allocated register size rather than terminating only on NUL bytes, closing all 2 injection vectors (oversized RSP register reply, truncated RSP register reply stack disclosure). Until patched, this is a concern on Linux systems running GDB clients connecting to remote RSP debug targets, so Only connect the GDB client to known, trusted debug targets and avoid attaching to unverified or hostile remote RSP stubs. As a compensating measure, Enforce SELinux in enforcing mode to confine the actions of a compromised GDB process, Deploy an EDR agent to detect anomalous process behavior and post-exploitation payloads spawned from GDB, Monitor kernel syscall activity via eBPF to detect unexpected commands or shells spawned by the GDB client, Enable Address Space Layout Randomization to randomize userspace memory addresses, and Enable the NX/XD bit to block direct shellcode execution from stack memory. These controls limit blast radius and contain exploitation, but they do not fix the underlying stack buffer overflow defect \u2014 apply the upstream patch to fully remediate.\n\nHighest-impact CME: CME-301 SELinux (Enforcing Mode) (medium)"
}
],
"x_generator": {
"engine": "cvelib 1.8.0"
},
"x_redhatCweChain": "CWE-121: Stack-based Buffer Overflow"
}
},
"cveMetadata": {
"assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
"assignerShortName": "redhat",
"cveId": "CVE-2026-121994",
"datePublished": "2026-11-05T16:08:46.589Z",
"dateReserved": "2026-11-04T13:28:12.838Z",
"dateUpdated": "2026-11-06T19:55:31.918Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-121994",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-11-05T17:25:53.959151Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-11-05T19:02:04.806Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:10"
],
"defaultStatus": "unaffected",
"packageName": "crash",
"product": "Red Hat Enterprise Linux 10",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:10"
],
"defaultStatus": "affected",
"packageName": "gdb",
"product": "Red Hat Enterprise Linux 10",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:rhel_els:6"
],
"defaultStatus": "affected",
"packageName": "gdb",
"product": "Red Hat Enterprise Linux 6",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/o:redhat:rhel_els:7"
],
"defaultStatus": "affected",
"packageName": "gdb",
"product": "Red Hat Enterprise Linux 7",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:8"
],
"defaultStatus": "unaffected",
"packageName": "crash",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:8"
],
"defaultStatus": "affected",
"packageName": "gcc-toolset-14-gdb",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:8"
],
"defaultStatus": "affected",
"packageName": "gcc-toolset-15-gdb",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:8"
],
"defaultStatus": "affected",
"packageName": "gdb",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:9"
],
"defaultStatus": "unaffected",
"packageName": "crash",
"product": "Red Hat Enterprise Linux 9",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:enterprise_linux:9"
],
"defaultStatus": "affected",
"packageName": "gdb",
"product": "Red Hat Enterprise Linux 9",
"vendor": "Red Hat"
},
{
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"cpes": [
"cpe:/a:redhat:hummingbird:1"
],
"defaultStatus": "affected",
"packageName": "gdb",
"product": "Red Hat Hardened Images",
"vendor": "Red Hat"
}
],
"credits": [
{
"lang": "en",
"value": "Red Hat would like to thank Pulkit Singh Singaria for reporting this issue."
}
],
"datePublic": "2026-11-05T14:25:22.606Z",
"descriptions": [
{
"lang": "en",
"value": "A stack buffer overflow in the GDB client\u0027s remote protocol handler allows an attacker-controlled debug target to execute arbitrary code in the GDB process. The vulnerability exists in fetch_register_using_p, which decodes a stub\u0027s register reply into an alloca-sized buffer without bounding writes by the register width."
}
],
"metrics": [
{
"other": {
"content": {
"namespace": "https://access.redhat.com/security/updates/classification/",
"value": "Important"
},
"type": "Red Hat severity rating"
}
},
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 8.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-121",
"description": "Stack-based Buffer Overflow",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-11-06T19:55:31.918Z",
"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
"shortName": "redhat"
},
"references": [
{
"tags": [
"vdb-entry",
"x_refsource_REDHAT"
],
"url": "https://access.redhat.com/security/cve/CVE-2026-121994"
},
{
"name": "RHBZ#2565676",
"tags": [
"issue-tracking",
"x_refsource_REDHAT"
],
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2565676"
}
],
"timeline": [
{
"lang": "en",
"time": "2026-10-21T08:41:10.000Z",
"value": "Reported to Red Hat."
},
{
"lang": "en",
"time": "2026-11-05T14:25:22.606Z",
"value": "Made public."
}
],
"title": "Gdb: gdb: stack buffer overflow in fetch_register_using_p via unchecked p-reply length",
"workarounds": [
{
"lang": "en",
"value": "There is no mitigation for this vulnerability. Users should only connect GDB to trusted debug targets.\n\n--- CME Mitigation Guidance (2026-11-06) ---\nDisclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure.\n\nThe highest-value action is to enforce bounds checking against register size when decoding remote serial protocol register replies in the GDB client remote protocol handler: upgrade to the corresponding fixed Red Hat builds, which bounds RSP register reply decoding to the allocated register size rather than terminating only on NUL bytes, closing all 2 injection vectors (oversized RSP register reply, truncated RSP register reply stack disclosure). Until patched, this is a concern on Linux systems running GDB clients connecting to remote RSP debug targets, so Only connect the GDB client to known, trusted debug targets and avoid attaching to unverified or hostile remote RSP stubs. As a compensating measure, Enforce SELinux in enforcing mode to confine the actions of a compromised GDB process, Deploy an EDR agent to detect anomalous process behavior and post-exploitation payloads spawned from GDB, Monitor kernel syscall activity via eBPF to detect unexpected commands or shells spawned by the GDB client, Enable Address Space Layout Randomization to randomize userspace memory addresses, and Enable the NX/XD bit to block direct shellcode execution from stack memory. These controls limit blast radius and contain exploitation, but they do not fix the underlying stack buffer overflow defect \u2014 apply the upstream patch to fully remediate.\n\nHighest-impact CME: CME-301 SELinux (Enforcing Mode) (medium)"
}
],
"x_generator": {
"engine": "cvelib 1.8.0"
},
"x_redhatCweChain": "CWE-121: Stack-based Buffer Overflow"
}
},
"cveMetadata": {
"assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
"assignerShortName": "redhat",
"cveId": "CVE-2026-121994",
"datePublished": "2026-11-05T16:08:46.589Z",
"dateReserved": "2026-11-04T13:28:12.838Z",
"dateUpdated": "2026-11-06T19:55:31.918Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
Loading timeline…
Loading…
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.