CVE-2026-53525

HIGH

7.4

CVSS v3

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.

CWE-208

How to fix

Remediation Available

weechatDebian

Fixed in:4.9.3-1CVE-2026-53525

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H

Exploit Intelligence

0.25%probability of exploitation in 30 days

17thpercentile

Low risk: more likely to be exploited than 17% of all known CVEs.

References

Other references1

github.com

Related Vulnerabilities

Other CWE-208 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2019-9494	Medium	5.9	3.9%	-	Fix
CVE-2019-16782	Medium	6.3	3.7%	-	Fix
CVE-2025-53940	Unscored	-	2.8%	-	-
CVE-2020-1926	Medium	5.9	2.5%	-	Fix
CVE-2021-43298	Critical	9.8	2.3%	-	Fix
CVE-2024-29995	High	8.1	1.5%	-	Fix

Common questions

How do I fix CVE-2026-53525?

Upgrade weechat on debian unstable to 4.9.3-1 or later.

Is CVE-2026-53525 being actively exploited?

Not that we know of. CVE-2026-53525 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.25% is the estimated probability that it will be exploited in the next 30 days. That is higher than 17% of all scored CVEs.

How severe is CVE-2026-53525?

CVE-2026-53525 has a CVSS v3 base score of 7.4, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-53525 affect?

Published advisories record a fix for weechat (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-25.