In xmlIO in libxml2 before 2.15.4, an inconsistency in xmlOutputWriteCallback and xmlBufUse causes negative lengths to reach write callbacks, aka a lack of a check for integer overflow before calling writecallback. This has security relevance for many types of uses of that length value within a callback.
History

Tue, 08 Sep 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Tue, 08 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
Title Integer Overflow in libxml2 Output Callbacks libxml2: libxml2: Data integrity issues due to integer overflow in write callbacks
Weaknesses CWE-190
References
Metrics threat_severity

None

threat_severity

Moderate


Sat, 05 Sep 2026 06:45:00 +0000

Type Values Removed Values Added
Title Integer Overflow in libxml2 Output Callbacks

Sat, 05 Sep 2026 04:45:00 +0000

Type Values Removed Values Added
Description In xmlIO in libxml2 before 2.15.4, an inconsistency in xmlOutputWriteCallback and xmlBufUse causes negative lengths to reach write callbacks, aka a lack of a check for integer overflow before calling writecallback. This has security relevance for many types of uses of that length value within a callback.
First Time appeared Xmlsoft
Xmlsoft libxml2
Weaknesses CWE-192
CPEs cpe:2.3:a:xmlsoft:libxml2:*:*:*:*:*:*:*:*
Vendors & Products Xmlsoft
Xmlsoft libxml2
References
Metrics cvssV3_1

{'score': 6.9, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published: 2026-09-05T04:31:21.187Z

Updated: 2026-09-08T18:06:25.507Z

Reserved: 2026-09-05T04:31:20.849Z

Link: CVE-2026-86143

cve-icon Vulnrichment

Updated: 2026-09-08T18:06:14.012Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-05T05:17:13.270

Modified: 2026-09-08T21:14:09.040

Link: CVE-2026-86143

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-09-05T04:31:21Z

Links: CVE-2026-86143 - Bugzilla