Libevent up to 2.2.1 WebSocket Session Management ws.c evws_new_session null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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3.2$0-$5k0.00

Summaryinfo

A vulnerability labeled as problematic has been found in Libevent up to 2.2.1. Impacted is the function evws_new_session of the file ws.c of the component WebSocket Session Management. The manipulation results in null pointer dereference. This vulnerability is identified as CVE-2026-63380. The attack is only possible with local access. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Libevent up to 2.2.1. Affected is the function evws_new_session of the file ws.c of the component WebSocket Session Management. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-63380 since 07/16/2026. The exploitability is told to be easy. The attack needs to be approached locally. There are known technical details, but no exploit is available.

Upgrading to version 2.2.2-alpha eliminates this vulnerability.

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Productinfo

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Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 3.3
VulDB Meta Temp Score: 3.2

VulDB Base Score: 3.3
VulDB Temp Score: 3.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Libevent 2.2.2-alpha

Timelineinfo

07/16/2026 CVE reserved
08/20/2026 +35 days Advisory disclosed
08/20/2026 +0 days VulDB entry created
08/20/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-63380 (🔒)
GCVE (CVE): GCVE-0-2026-63380
GCVE (VulDB): GCVE-100-393816

Entryinfo

Created: 08/20/2026 20:13
Changes: 08/20/2026 20:13 (68)
Complete: 🔍
Cache ID: 216::103

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