CVE-2026-113799 (GCVE-0-2026-113799)
Vulnerability from cvelistv5
Published
2026-10-21 16:15
Modified
2026-10-21 16:15
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-532 - Insertion of Sensitive Information into Log File
Summary
Slack Morphism is a client library for Slack Web/Events API/Socket Mode and Block Kit. Versions 1.0.0 through 2.27.0 expose the correct Slack request HMAC when signature verification fails. For an invalid request, `slack-morphism` computes the correct signature for the attacker-controlled timestamp and request body and stores it in `SlackEventWrongSignatureError.generated_hash`. The error's `Debug` and `Display` representations expose that value, and the default Axum listener error handler logs it at error level. An attacker who can both reach the application's Slack callback endpoint and read its application/service logs can therefore use the verifier as a chosen-message HMAC oracle. The attacker can send an arbitrary request with an invalid signature, recover the correct signature from the resulting log entry, and resend the same request within the five-minute freshness window. The second request passes Slack Morphism's signature verification and reaches the protected application callback without the attacker knowing the Slack signing secret. Version 2.28.0 patches the issue.
References
| URL | Tags | |
|---|---|---|
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Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| abdolence | slack-morphism-rust |
Version: >= 1.0.0, < 2.28.0 |
{
"containers": {
"cna": {
"affected": [
{
"product": "slack-morphism-rust",
"vendor": "abdolence",
"versions": [
{
"status": "affected",
"version": "\u003e= 1.0.0, \u003c 2.28.0"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Slack Morphism is a client library for Slack Web/Events API/Socket Mode and Block Kit. Versions 1.0.0 through 2.27.0 expose the correct Slack request HMAC when signature verification fails. For an invalid request, `slack-morphism` computes the correct signature for the attacker-controlled timestamp and request body and stores it in `SlackEventWrongSignatureError.generated_hash`. The error\u0027s `Debug` and `Display` representations expose that value, and the default Axum listener error handler logs it at error level. An attacker who can both reach the application\u0027s Slack callback endpoint and read its application/service logs can therefore use the verifier as a chosen-message HMAC oracle. The attacker can send an arbitrary request with an invalid signature, recover the correct signature from the resulting log entry, and resend the same request within the five-minute freshness window. The second request passes Slack Morphism\u0027s signature verification and reaches the protected application callback without the attacker knowing the Slack signing secret. Version 2.28.0 patches the issue."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-532",
"description": "CWE-532: Insertion of Sensitive Information into Log File",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-10-21T16:15:10.051Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/abdolence/slack-morphism-rust/security/advisories/GHSA-26w4-8w32-4x3v",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/abdolence/slack-morphism-rust/security/advisories/GHSA-26w4-8w32-4x3v"
},
{
"name": "https://github.com/abdolence/slack-morphism-rust/pull/387",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/abdolence/slack-morphism-rust/pull/387"
},
{
"name": "https://github.com/abdolence/slack-morphism-rust/commit/ac95d0d4539d0eac548a8db99c51c0c1ae832756",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/abdolence/slack-morphism-rust/commit/ac95d0d4539d0eac548a8db99c51c0c1ae832756"
},
{
"name": "https://github.com/abdolence/slack-morphism-rust/releases/tag/v2.28.0",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/abdolence/slack-morphism-rust/releases/tag/v2.28.0"
}
],
"source": {
"advisory": "GHSA-26w4-8w32-4x3v",
"discovery": "UNKNOWN"
},
"title": "Slack Morphism verifier errors disclose valid HMACs in the logs"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-113799",
"datePublished": "2026-10-21T16:15:10.051Z",
"dateReserved": "2026-10-20T17:39:41.373Z",
"dateUpdated": "2026-10-21T16:15:10.051Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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