What’s Vulnerable › Vulnerabilities

CVE-2021-40516

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-09-05 · updated 2026-06-17
• Weakness: CWE-125

Description

WeeChat before 3.2.1 allows remote attackers to cause a denial of service (crash) via a crafted WebSocket frame that trigger an out-of-bounds read in plugins/relay/relay-websocket.c in the Relay plugin.

Affected products

• Debian Linux: 10.0
• weechat: from 0.4.1 before 3.2.1 — fixed in 3.2.1

How to fix

Upgrade to a fixed version: weechat 3.2.1. Check the vendor advisory for mitigations.

References

• https://github.com/weechat/weechat/commit/8b1331f98de1714bae15a9ca2e2b393ba49d735b
• https://lists.debian.org/debian-lts-announce/2021/09/msg00018.html
• https://weechat.org/doc/security/
• https://github.com/weechat/weechat/commit/8b1331f98de1714bae15a9ca2e2b393ba49d735b
• https://lists.debian.org/debian-lts-announce/2021/09/msg00018.html
• https://weechat.org/doc/security/

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