What's the vulnerability?
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.
Business impact & how R4IM helps
This advisory is on our active-exploitation watchlist. Attackers are using it for initial access, privilege escalation or lateral movement in real-world intrusions. R4IM's offensive security and SOC teams already have detections, exploit replicas and remediation playbooks for this issue.
Targeted vulnerability assessment to confirm which of your assets are actually exploitable — not just theoretically affected.
Our pentesters chain this CVE into realistic attack paths so you see business impact, not just a scan finding.
If the affected product is internet-facing, our AppSec team will harden it against this and related OWASP-class issues.
Continuous monitoring with custom detections for this CVE deployed across your endpoints, identity and cloud.
Recommended remediation
- Inventory all assets running the affected vendor and product, including shadow IT and third-party hosted instances.
- Apply the vendor patch or mitigation referenced in the advisories below. Where no patch exists, isolate the asset or restrict network exposure.
- Hunt for indicators of prior compromise — exploitation of this class of bug often predates public disclosure.
- Deploy detections for the exploit primitives (network signature, EDR rule, WAF rule) and re-test after remediation.
Need help executing these steps? Our team typically completes validation and remediation within a single patch cycle. Request remediation support →
Vendor & research references
- https://cna.erlef.org/cves/CVE-2026-65629.html · 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
- https://github.com/potatosalad/erlang-jose/commit/461b261902531ca016190e780bb70862d561a7e0 · 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
- https://github.com/potatosalad/erlang-jose/commit/85fddd89ee56b6f9c19eff7d9cfffeef62c330b9 · 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
- https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-h4gx-8jq2-mfhc · 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
- https://osv.dev/vulnerability/EEF-CVE-2026-65629 · 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
- https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-h4gx-8jq2-mfhc · 134c704f-9b21-4f2e-91b3-4a467353bcc0
