# CVE-2026-9638: Crypt::PBKDF2 versions before 0.261630 for Perl generate insecure random values for salts

> The Perl Crypt::PBKDF2 library uses predictable random values for salts, weakening password hashing security and potentially aiding brute-force attacks.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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:** 12 Jun 2026
- **Also known as:** DEBIAN-CVE-2026-9638, GHSA-3rw7-pf56-37cv, UBUNTU-CVE-2026-9638

## What is CVE-2026-9638?

CVE-2026-9638 is a high-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 generate insecure random values for salts.

These versions use the built-in rand function, which is predictable and unsuitable for cryptography.

Weakness: CWE-338 (Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG))

## Which versions are affected by CVE-2026-9638?


## How do I fix CVE-2026-9638?

Upgrade to a fixed version.

## Is CVE-2026-9638 being exploited?

There is no known exploitation of CVE-2026-9638 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-9638 and fix it if it is affected.

What it is: CVE-2026-9638 is a high-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-2026-9638 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-2026-9638/ (Markdown: https://insights.sbomify.com/CVE-2026-9638/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-9638
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-9638
- OSV: https://osv.dev/vulnerability/CVE-2026-9638

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-9638/
Summaries are generated and may contain mistakes; the official description above is the record.