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.

MediumVendor CVSS 6.9 / 10 1 CVE Published Sep 6, 2026 at 4:36 AM UTC

Summary

Mariner

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Sep 6, 2026 at 4:36 AM UTC
Published by Microsoft Security Response Center
The publication date reported by the vendor.
Sep 8, 2026 at 7:05 AM UTC
Added to SecurityAlert
We collected the advisory from the official source.
Sep 19, 2026 at 1:58 AM UTC
Updated by Microsoft Security Response Center
The vendor changed the advisory after it was first published.
Oct 28, 2026 at 3:45 AM UTC
Confirmed at the source
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Details collected from Microsoft Security Response Center.

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