# CVE-2026-53525: WeeChat has Non-Constant-Time Password Hash Comparison in Relay Authentication

> Attackers can bypass relay authentication in WeeChat by exploiting timing side-channels in password hash comparison to extract hashes and gain access.

- **Severity:** High 7.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Aug 2026
- **Updated:** 25 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-53525, GHSA-vhv8-g2r9-cwcc, UBUNTU-CVE-2026-53525

## What is CVE-2026-53525?

CVE-2026-53525 is a high-severity vulnerability in weechat, published on 21 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-208 (Observable Timing Discrepancy)

## Which versions are affected by CVE-2026-53525?


## How do I fix CVE-2026-53525?

Upgrade to a fixed version.

## Is CVE-2026-53525 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-53525 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53525 and fix it if it is affected.

What it is: CVE-2026-53525 is a high-severity vulnerability in weechat, published on 21 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-53525 exists.

Affected product: weechat. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-53525/ (Markdown: https://insights.sbomify.com/CVE-2026-53525/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53525
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53525
- OSV: https://osv.dev/vulnerability/CVE-2026-53525

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53525/
Summaries are generated and may contain mistakes; the official description above is the record.