VulnerabilityDeferred

CVE-2026-53525

An attacker can exploit timing differences to extract the server-computed hash character by character, then authenticate using the correct hash without knowing the password.

HIGH 7.4EPSS 0.25%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.25%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

WeeChat (Wee Enhanced Environment for Chat) is a free chat client. In versions 0.3.1 through 4.9.0, the WeeChat relay authentication uses non-constant-time string comparison functions (weechat_strcasecmp and strcmp) to verify password hashes and plaintext passwords. An attacker can exploit timing differences to extract the server-computed hash character by character, then authenticate using the correct hash without knowing the password. Version 4.9.1 fixes the issue.

CVSS 3.1: 7.4 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H
EPSS: 0.25% probability · 17th percentile
CISA KEV: Not listed
Weakness: CWE-208
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.