# CVE-2026-2543: vichan-devel vichan Password Change pages.php unverified password change

> Attackers can change user passwords without verification in vichan-devel, leading to account takeover.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Feb 2026
- **Updated:** 23 Feb 2026
- **Also known as:** GHSA-c68v-2764-rf86

## What is CVE-2026-2543?

CVE-2026-2543 is a medium-severity authentication bypass vulnerability in vichan-devel vichan, published on 16 Feb 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

A vulnerability was identified in vichan-devel vichan up to 5.1.5. This vulnerability affects unknown code of the file inc/mod/pages.php of the component Password Change Handler. The manipulation of the argument Password leads to unverified password change. The attack can be initiated remotely. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-640 (Weak Password Recovery Mechanism for Forgotten Password), CWE-620 (Unverified Password Change)

## Which versions are affected by CVE-2026-2543?


## How do I fix CVE-2026-2543?

No fix has been published for CVE-2026-2543 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-2543 being exploited?

There is no known exploitation of CVE-2026-2543 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-2543 and fix it if it is affected.

What it is: CVE-2026-2543 is a medium-severity authentication bypass vulnerability in vichan-devel vichan, published on 16 Feb 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-2543 in the wild and no public exploit code.

Affected product: vichan-devel vichan. 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-2026-2543/ (Markdown: https://insights.sbomify.com/CVE-2026-2543/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-2543
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-2543
- OSV: https://osv.dev/vulnerability/CVE-2026-2543

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-2543/
Summaries are generated and may contain mistakes; the official description above is the record.