CVE-2026-86143
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.
- Published Sep 5, 2026
- CVSS 7.3 high
- 0.2% chance of exploitation in the next 30 days (EPSS)
- Public exploit code is available
- A fix is available