VDB
CVE-2026-63383
CVE-2026-63383
PUBLISHED
CVSS 8.7 HIGH
Reported by GitHub_M · Published August 20, 2026
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.
Risk Scores
CVSS 4.0
8.7
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
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| libevent | libevent | >= 2.2.0-alpha, < 2.2.2-alpha, < 2.1.13 |
| libevent | libevent | >= 2.2.0-alpha, < 2.2.2-alpha, < 2.1.13 |
Timeline
- Aug 20, 2026 CVE Published
- Aug 22, 2026 Coalition ESS Score
- Aug 24, 2026 EPSS Score
- Aug 26, 2026 EPSS Score
- Aug 30, 2026 EPSS Score
- Sep 3, 2026 Security Advisory
- Sep 4, 2026 EPSS Score
- Sep 9, 2026 EPSS Score
- Sep 9, 2026 CVE Updated
- Sep 12, 2026 EPSS Score
- Sep 16, 2026 EPSS Score
- Sep 18, 2026 EPSS Score
References
- https://github.com/libevent/libevent/security/advisories/GHSA-fj29-64w6-73h6 x_refsource_CONFIRM
- https://github.com/libevent/libevent/commit/91ed8745eebabdd27592a83d350338a8c4626321 x_refsource_MISC
- https://github.com/libevent/libevent/commit/e1f9e21887c6b104e206a718385ba3ffc75180cb x_refsource_MISC
- https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable x_refsource_MISC
- https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha x_refsource_MISC