Medium
Security advisory
libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_ResumeParser from within handlers in cases of a policy violation. Thus, a use-after-free can occur (similar to the CVE-2026-50219 situation).
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-56131
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 10:08 UTC · Revision 1
Source evidence
libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_ResumeParser from within handlers in cases of a policy violation. Thus, a use-after-free can occur (similar to the CVE-2026-50219 situation).
osv:CVE-2026-56131
Complete source record
{
"id": "72a7df3b235962f05cced836f74bfec32c1658f40b98b6a70378cf856356b4b4",
"url": "https://osv.dev/vulnerability/CVE-2026-56131",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2026-56131",
"summary": "libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_ResumeParser from within handlers in cases of a policy violation. Thus, a use-after-free can occur (similar to the CVE-2026-50219 situation).",
"evidence": "osv:CVE-2026-56131",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2026-56131",
"aliases": [
"CVE-2026-56131"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/libexpat/libexpat",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "c61098da494eea1cbd091118118dcee417faacea"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "2.8.2"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
},
{
"cpe": "cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "2.8.2"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"R_2_8_1",
"R_2_8_0",
"R_2_7_5",
"R_2_7_4",
"R_2_7_3",
"R_2_7_2",
"R_2_7_1",
"R_2_7_0",
"R_2_6_4",
"R_2_6_3",
"R_2_6_2",
"R_2_6_1",
"R_2_6_0",
"R_2_5_0",
"R_2_4_9",
"R_2_4_8",
"R_2_4_7",
"R_2_4_6",
"R_2_4_5",
"R_2_4_4",
"R_2_4_3",
"R_2_4_2",
"R_2_4_1",
"R_2_4_0",
"R_2_3_0",
"R_2_2_10",
"R_2_2_9",
"R_2_2_8",
"R_2_2_7",
"R_2_2_6",
"R_2_2_5",
"R_2_2_4",
"R_2_2_3",
"R_2_2_2",
"R_2_2_1",
"R_2_2_0",
"R_2_1_1",
"R_2_1_0",
"R_2_0_1",
"R_2_0_0",
"R_1_95_8",
"R_1_95_7",
"R_1_95_6",
"R_1_95_5",
"R_1_95_4",
"R_1_95_3",
"R_1_95_2",
"R_1_95_0",
"libexpat-alpha-1",
"start",
"sourceforge_init",
"jclark-orig",
"V20000512",
"V19991013",
"V19990728",
"V19990709",
"V19990626",
"V1_1",
"V19990425",
"V1990307",
"V19990109",
"V19981231",
"V19981122",
"V1_0",
"beta4",
"beta3",
"beta2",
"REC1_0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-56131.json"
}
}
],
"modified": "2026-10-28T02:30:27.582887097Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56131.json",
"https://nvd.nist.gov/vuln/detail/CVE-2026-56131",
"https://github.com/libexpat/libexpat/pull/1267"
],
"provider_metadata": {
"cwe_ids": [
"CWE-416"
],
"cna_assigner": "mitre",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56131.json"
}
},
"related_cves": [
{
"value": "CVE-2026-56131",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 494391,
"published_at": "2026-06-19T02:56:36.041+00:00"
}