CVE-2026-63383
CVE-2026-63383
Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent can read beyond a contiguous evbuffer region in event_tagging.c when decode_tag_internal requests at most five bytes from evbuffer_pullup but iterates using the full logical buffer length. A fragmented evbuffer containing a six-byte malformed tag can therefore advance past the pullup window and trigger an out-of-bounds read, which can crash a process that decodes attacker-controlled tagged RPC data. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.
Vulnerability class: Buffer Overflow
Published · last modified .
EPSS exploit prediction
EPSS: 0.005 (42.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 42.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001
Weakness classification (CWE)
References
- github.com/libevent/libevent/security/advisories/GHSA-fj29-64w6-73h6
- github.com/libevent/libevent/commit/91ed8745eebabdd27592a83d350338a8c4626321
- github.com/libevent/libevent/commit/e1f9e21887c6b104e206a718385ba3ffc75180cb
- github.com/libevent/libevent/releases/tag/release-2.1.13-stable
- github.com/libevent/libevent/releases/tag/release-2.2.2-alpha