CVE-2026-53525

HIGHCVSS 7.4/10EPSS 0.25%

Last modified

CVE-2026-53525 is a high-severity vulnerability rated 7.4/10 on the CVSS scale. 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. EPSS estimates a 0.25% chance of exploitation in the next 30 days.

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.

Metrics

EPSS Probability
0.25%

16.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
weechatweechat>= 0.3.4, < 4.9.1

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-53525?
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.
How severe is CVE-2026-53525?
CVE-2026-53525 has a CVSS score of 7.4/10 (HIGH severity). The EPSS model estimates a 0.25% probability of exploitation in the next 30 days.
How do I fix CVE-2026-53525?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST