CVE-2026-63383Libevent: decode_tag_internal() can lead to out-of-bounds read
Updated under an hour ago ()
Does this affect you?
It affects libevent. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
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.
- CVSS
- 8.7 HIGH (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- Weakness (CWE)
- CWE-125
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Awaiting Analysis
- Record last updated
- Aug 20, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
libevent libevent libevent:libevent (from the name) | from 2.2.0-alpha, < 2.2.2-alpha; before 2.1.13 | CNA record |
References
- https://github.com/libevent/libevent/security/advisories/GHSA-fj29-64w6-73h6x-refsource-confirm
- https://github.com/libevent/libevent/commit/91ed8745eebabdd27592a83d350338a8c4626321x-refsource-misc
- https://github.com/libevent/libevent/commit/e1f9e21887c6b104e206a718385ba3ffc75180cbx-refsource-misc
- https://github.com/libevent/libevent/releases/tag/release-2.1.13-stablex-refsource-misc
- https://github.com/libevent/libevent/releases/tag/release-2.2.2-alphax-refsource-misc
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.