# CVE-2026-91995: pig before 4.1.0 Unverified Password Change via /register/password

> Attackers can bypass password verification to overwrite any account credentials, including admin, gaining full control.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Sep 2026
- **Updated:** 24 Sep 2026
- **Also known as:** GHSA-7g92-2j5x-mj6h

## What is CVE-2026-91995?

CVE-2026-91995 is a critical authentication bypass vulnerability in pig-mesh pig, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

pig before 4.1.0 contains an authentication bypass vulnerability in the /register/password endpoint where password verification results are discarded, allowing any value as the current password. Remote attackers can submit a username with an incorrect current password to overwrite any account credential including the admin account and gain full administrative control.

Weakness: CWE-620 (Unverified Password Change)

## Which versions are affected by CVE-2026-91995?


## How do I fix CVE-2026-91995?

No fix has been published for CVE-2026-91995 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-91995 being exploited?

There is no known exploitation of CVE-2026-91995 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-91995 and fix it if it is affected.

What it is: CVE-2026-91995 is a critical authentication bypass vulnerability in pig-mesh pig, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-91995 in the wild and no public exploit code.

Affected product: pig-mesh pig. 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-2026-91995/ (Markdown: https://insights.sbomify.com/CVE-2026-91995/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-91995
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-91995
- OSV: https://osv.dev/vulnerability/CVE-2026-91995

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-91995/
Summaries are generated and may contain mistakes; the official description above is the record.