# CVE-2026-9641: Crypt::PBKDF2 versions before 0.261630 for Perl have a weak default algorithm and number of iterations

> Weak default PBKDF2 settings in Perl library allow attackers to more easily crack hashed passwords.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Jun 2026
- **Updated:** 14 Jun 2026
- **Also known as:** DEBIAN-CVE-2026-9641, GHSA-v9r4-9w2c-2xcp, UBUNTU-CVE-2026-9641

## What is CVE-2026-9641?

CVE-2026-9641 is a medium-severity vulnerability in ARODLAND Crypt::PBKDF2, published on 12 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Crypt::PBKDF2 versions before 0.261630 for Perl have a weak default algorithm and number of iterations.

The default algorithm is HMAC-SHA1, which should only be used for legacy systems.

These versions default to using 1000 iterations.

Depending on the chosen algorithm, 220,000 to 1,400,000 iterations should be used.

Weakness: CWE-916 (Use of Password Hash With Insufficient Computational Effort)

## Which versions are affected by CVE-2026-9641?


## How do I fix CVE-2026-9641?

Upgrade to a fixed version.

## Is CVE-2026-9641 being exploited?

There is no known exploitation of CVE-2026-9641 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-9641 and fix it if it is affected.

What it is: CVE-2026-9641 is a medium-severity vulnerability in ARODLAND Crypt::PBKDF2, published on 12 Jun 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-2026-9641 in the wild and no public exploit code.

Affected product: ARODLAND Crypt::PBKDF2. 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-2026-9641/ (Markdown: https://insights.sbomify.com/CVE-2026-9641/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-9641
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-9641
- OSV: https://osv.dev/vulnerability/CVE-2026-9641

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-9641/
Summaries are generated and may contain mistakes; the official description above is the record.