CVE-2026-5089 (GCVE-0-2026-5089)
Vulnerability from cvelistv5
Published
2026-05-12 16:14
Modified
2026-05-14 13:51
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-124 - Buffer Underwrite ('Buffer Underflow')
Summary
YAML::Syck versions before 1.38 for Perl has an out-of-bounds read.
The base60 (sexagesimal) parsing code in perl_syck.h has a buffer underflow bug in both int#base60 and float#base60 handlers. When processing the leftmost segment of a colon-separated value (e.g., the 1 in 1:30:45), the inner while loop can decrement a pointer past the start of the string buffer:
while ( colon >= ptr && *colon != ':' )
{
colon--;
}
if ( *colon == ':' ) *colon = '\0'; // colon may be ptr-1 here
When no colon is found (final/leftmost segment), colon becomes ptr-1, and the subsequent *colon dereference reads one byte before the allocated buffer.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| TODDR | YAML::Syck |
Version: 0 < 1.38 |
{
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"providerMetadata": {
"dateUpdated": "2026-05-12T18:35:46.042Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
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"url": "http://www.openwall.com/lists/oss-security/2026/05/12/16"
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"title": "CVE Program Container"
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{
"metrics": [
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"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "LOW",
"baseScore": 7.3,
"baseSeverity": "HIGH",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"version": "3.1"
}
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"content": {
"id": "CVE-2026-5089",
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{
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],
"role": "CISA Coordinator",
"timestamp": "2026-05-14T13:50:53.123874Z",
"version": "2.0.3"
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}
}
],
"providerMetadata": {
"dateUpdated": "2026-05-14T13:51:01.952Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"references": [
{
"tags": [
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],
"url": "https://github.com/cpan-authors/YAML-Syck/issues/132"
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{
"collectionURL": "https://cpan.org/modules",
"defaultStatus": "unaffected",
"packageName": "YAML-Syck",
"product": "YAML::Syck",
"programFiles": [
"perl_syck.h"
],
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"vendor": "TODDR",
"versions": [
{
"lessThan": "1.38",
"status": "affected",
"version": "0",
"versionType": "custom"
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"value": "YAML::Syck versions before 1.38 for Perl has an out-of-bounds read.\n\nThe base60 (sexagesimal) parsing code in perl_syck.h has a buffer underflow bug in both int#base60 and float#base60 handlers. When processing the leftmost segment of a colon-separated value (e.g., the 1 in 1:30:45), the inner while loop can decrement a pointer past the start of the string buffer:\n\n while ( colon \u003e= ptr \u0026\u0026 *colon != \u0027:\u0027 )\n {\n colon--;\n }\n if ( *colon == \u0027:\u0027 ) *colon = \u0027\\0\u0027; // colon may be ptr-1 here\n\nWhen no colon is found (final/leftmost segment), colon becomes ptr-1, and the subsequent *colon dereference reads one byte before the allocated buffer."
}
],
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"descriptions": [
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"cweId": "CWE-124",
"description": "CWE-124 Buffer Underwrite (\u0027Buffer Underflow\u0027)",
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"type": "CWE"
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}
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"dateUpdated": "2026-05-12T16:14:21.951Z",
"orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
"shortName": "CPANSec"
},
"references": [
{
"tags": [
"release-notes"
],
"url": "https://metacpan.org/release/TODDR/YAML-Syck-1.38/changes"
},
{
"tags": [
"issue-tracking"
],
"url": "https://github.com/cpan-authors/YAML-Syck/issues/132"
},
{
"tags": [
"issue-tracking"
],
"url": "https://github.com/cpan-authors/YAML-Syck/pull/133"
},
{
"tags": [
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],
"url": "https://github.com/cpan-authors/YAML-Syck/commit/208a4d3bd1b5cdb4a791a6e3905bd6bd45e9d005.patch"
}
],
"solutions": [
{
"lang": "en",
"value": "Upgrade to YAML::Syck version 1.38 or later."
}
],
"source": {
"discovery": "UNKNOWN"
},
"title": "YAML::Syck versions before 1.38 for Perl has an out-of-bounds read",
"x_generator": {
"engine": "cpansec-cna-tool 0.1"
}
}
},
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"assignerShortName": "CPANSec",
"cveId": "CVE-2026-5089",
"datePublished": "2026-05-12T16:14:21.951Z",
"dateReserved": "2026-03-28T19:33:37.653Z",
"dateUpdated": "2026-05-14T13:51:01.952Z",
"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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