Libevent: Null Pointer Dereference in `evws_new_session` (libevent libevent)

CVE-2026-63380
MEDIUM 5.7

At a glance

Source
NVD
EPSS
EPSS 0.14 % · percentile 3 ()
State
PUBLISHED
Published
Updated
Assigner
GitHub_M
NVD status
Awaiting Analysis

Description

Libevent is an event notification library. Prior to 2.2.2-alpha, libevent can dereference invalid list pointers in ws.c when evws_new_session enters its error path after evhttp_start_ws_ succeeds but bufferevent_enable_locking_ fails. evws_connection_free sees a non-null http_server and unconditionally calls TAILQ_REMOVE even though the session was never inserted into http_server->ws_sessions. A local caller able to induce this allocation or locking failure can crash the process. This issue is fixed in version 2.2.2-alpha.

Weaknesses (CWE)

  • CWE-416 — Use After Free
  • CWE-476 — NULL Pointer Dereference

References

Scores

VersionScoreVectorScored by
CVSS 4.0MEDIUM 5.7CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NGitHub_M
CVSS 4.0MEDIUM 5.7CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XNVD · security-advisories@github.com (Secondary)

European references

CERT-FR advisories

Affected products

ProductVersions
libevent · libeventaffected < 2.2.2-alpha

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD