CVE-2026-65630 Affecting erlang-jose package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DEBIAN12-ERLANGJOSE-21757308
- published28 Oct 2026
- disclosed26 Oct 2026
Introduced: 26 Oct 2026
NewCVE-2026-65630 (opens in a new tab)How to fix?
There is no fixed version for Debian:12 erlang-jose.
NVD Description
Note: Versions mentioned in the description apply only to the upstream erlang-jose package and not the erlang-jose package as distributed by Debian.
See How to fix? for Debian:12 relevant fixed versions and status.
Observable Timing Discrepancy vulnerability in potatosalad jose allows recovery of a long-term X25519 private key through a timing side channel in the pure-Erlang Curve25519 fallback.
The pure-Erlang X25519 implementation performs scalar multiplication over the secret private key using a recursive Montgomery ladder (jose_jwa_x25519:curve25519/2) whose clauses branch on individual bits of the clamped private scalar, and whose per-step operations (jose_jwa_x25519:montgomery_add/3 and jose_jwa_x25519:montgomery_double/1) and field inversion are built from value-dependent Erlang bignum arithmetic (multiplication, remainder, and modular exponentiation). Although the ladder is operation-count balanced and fixed at 254 steps, the concrete integer values processed at each step, and therefore the running time, depend on the secret scalar. The execution time of the public entry points jose_jwa_x25519:scalarmult/2, jose_jwa_x25519:x25519/2, jose_jwa_x25519:x25519_base/1, and jose_jwa_x25519:sk_to_pk/1 is thus a function of the private key.
This path is reachable from the public API, most notably when a service decrypts attacker-supplied ECDH-ES (JWE) messages with a long-term X25519 key (for example through JOSE.JWK.box_decrypt_ecdh_es/2, which reaches jose_jwa_curve25519:x25519_shared_secret/2 and the ladder). An attacker who can submit ciphertexts and measure decryption timing can, in principle, recover the private key bit by bit, defeating the resistance X25519 was designed to provide. Recovery of the key compromises the confidentiality and authenticity of all data protected by it.
This issue affects jose: from 1.10.0 before 1.11.13.
References
- https://security-tracker.debian.org/tracker/CVE-2026-65630
- https://cna.erlef.org/cves/CVE-2026-65630.html
- https://github.com/potatosalad/erlang-jose/commit/3670f873c274bba86fb7f5ee5727a7efa1322b79
- https://github.com/potatosalad/erlang-jose/commit/8e532095de114ef4bf88a9ec5d651fa251a972b3
- https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-xvr2-gggj-h2pp
- https://osv.dev/vulnerability/EEF-CVE-2026-65630