Out-of-bounds Read Affecting libevent package, versions <2.1.12-stable-10+e1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.49% (41st percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-ECHOLATEST-LIBEVENT-19166021
  • published22 Aug 2026
  • disclosed20 Aug 2026

Introduced: 20 Aug 2026

CVE-2026-63383  (opens in a new tab)
CWE-125  (opens in a new tab)

How to fix?

Upgrade Echo:latest libevent to version 2.1.12-stable-10+e1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libevent package and not the libevent package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

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 Base Scores

version 3.1