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Vulnerabilities

Vulnerability · CVE-2026-65632

The jose library accepts ECDSA (ES256, ES256K, ES384, and ES512) JWS signatures of a non-canonical length.

Published Oct 26, 2026 · catalog updated Oct 27, 2026 · The jose library accepts

Last checked Nov 5, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-65632. EPSS is 0.09%. Act only if a listed version of The jose library accepts is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (The jose library accepts).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Unknown—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.09%
Remediation
Advisory link
Affected products
Debian:12 erlang-jose · Debian:13 erlang-jose · Debian:14 erlang-jose · Hex jose

The jose library accepts ECDSA (ES256, ES256K, ES384, and ES512) JWS signatures of a non-canonical length. When verifying an ECDSA signature, jose_jwk_kty_ec:verify/4 in src/jwk/jose_jwk_kty_ec.erl splits the raw signature in half by its actual byte length (split_binary(Signature, byte_size(Signature) div 2)) instead of enforcing the fixed length required by RFC 7518 §3.4, and then decodes each half with crypto:bytes_to_integer/1, which ignores leading zero bytes. As a result, an attacker who holds one valid token can prepend leading zero bytes to each of the R and S halves to produce longer signatures that still split evenly and decode to the same (r, s) pair, so many distinct signature byte strings all verify against the same key (signature malleability). This does not allow forging new payloads or impersonating a signer, because the underlying (r, s) values are unchanged. It does defeat any security control that assumes a valid token or its signature is unique, such as token-revocation-by-hash, replay or idempotency caches, and deduplication logic. This issue affects jose: from 1.0.0 before 1.11.13.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Debian:12 erlang-jose1.11.10-1, 1.11.10-1~bpo12+1, 1.11.12-1
  • Debian:13 erlang-jose1.11.10-1, 1.11.12-1, 1.11.12-1.1
  • Debian:14 erlang-jose1.11.10-1, 1.11.12-1, 1.11.12-1.1
  • Hex jose1.0.0 → 1.11.13

How to fix CVE-2026-65632

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-65632. EPSS is 0.09%. Act only if a listed version of The jose library accepts is installed.

Which versions are affected?

Compare what you have installed with 1.11.10-1, 1.11.10-1~bpo12+1, 1.11.12-1, 1.11.10-1, 1.11.12-1, 1.11.12-1.1, 1.0.0 → 1.11.13. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-347: Improper Verification of Cryptographic Signature. EPSS 0.09%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Debian securityUbuntu security

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 26, 2026 · GitHub Advisory Database

    Fix available

    jose fixed in 1.11.13

  2. Oct 26, 2026 · Trivy Vulnerability DB

    Detected

    The jose library accepts ECDSA (ES256, ES256K, ES384, and ES512) JWS signatures of a non-canonical length. When verifying an ECDSA signature, jose_jwk_kty_ec:verify/4 in src/jwk/jose_jwk_kty_ec.erl splits the raw signature in half by its actual byte length (split_binary(Signature, byte_size(Signature) div 2)) instead of enforcing the fixed length required by RFC 7518 §3.4, and then decodes each ha

  3. Oct 27, 2026 · GitHub Advisory Database

    Fix available

    jose fixed in 1.11.13

  4. Oct 27, 2026 · Trivy Vulnerability DB

    Updated

    The jose library accepts ECDSA (ES256, ES256K, ES384, and ES512) JWS signatures of a non-canonical length. When verifying an ECDSA signature, jose_jwk_kty_ec:verify/4 in src/jwk/jose_jwk_kty_ec.erl splits the raw signature in half by its actual byte length (split_binary(Signature, byte_size(Signature) div 2)) instead of enforcing the fixed length required by RFC 7518 §3.4, and then decodes each ha

Sources

  • CVE.orgVulnerability recordCVE-2026-65632

    Official CVE identifier

    cve.org
  • GitHub Advisory DatabasePackage advisoryGHSA-44hw-rpw9-mwg4

    GitHub Advisory Database record mirrored by OSV.

    github.com
  • OpenSSF OSV / OSV ScannerPackage advisoryEEF-CVE-2026-65632

    ECDSA signature length is not validated in jose, allowing signature malleability

    osv.dev
  • Trivy Vulnerability DBPackage advisoryDEBIAN-CVE-2026-65632

    The jose library accepts ECDSA (ES256, ES256K, ES384, and ES512) JWS signatures of a non-canonical length. When verifying an ECDSA signature, jose_jwk_kty_ec:verify/4 in src/jwk/jose_jwk_kty_ec.erl splits the raw signature in half by its actual byte length (split_binary(Signature

    osv.dev

References

Freshness

Last verified in this catalog Nov 5, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • GitHub Advisory DatabaseOct 30, 2026
  • OpenSSF OSV / OSV ScannerOct 30, 2026
  • CVE.orgOct 27, 2026
  • Trivy Vulnerability DBOct 27, 2026