Vulnerabilities

Vulnerability · CVE-2026-65625

The pure-Erlang AES-GCM fallback in jose_jwa_aes derives the number of verified authentication tag bits from the attacker-supplied tag itself.

Published Oct 26, 2026 · catalog updated Oct 27, 2026 · The pure-Erlang AES-GCM fallback

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-2026-65625. EPSS is 0.11%. Act only if a listed version of The pure-Erlang AES-GCM fallback 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 pure-Erlang AES-GCM fallback).
  • 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
0.11%
Remediation
Advisory link
Affected products
Debian:12 erlang-jose · Debian:13 erlang-jose · Debian:14 erlang-jose

The pure-Erlang AES-GCM fallback in jose_jwa_aes derives the number of verified authentication tag bits from the attacker-supplied tag itself. In the {aes_gcm, Bits} clause of block_decrypt/4, the incoming tag is guarded only by is_binary/1, with no check on its length. Verification in gcm_block_decrypt/6 then computes TBits = bit_size(T) and compares only those bits of the real 128-bit tag. An attacker who controls a JWE token can truncate the authentication tag to as little as 8 bits, so only 8 bits are ever checked. This reduces forgery resistance from 2^-128 to 2^-8, and a forged ciphertext is reliably accepted as authentic within 256 attempts without knowledge of the key (an authentication tag forgery and integrity bypass). Supplying a tag longer than 128 bits instead causes a badmatch that crashes the decrypting process. The fallback is reached through the public JWE decryption path whenever AES-GCM is not provided by a native crypto NIF, for example on FIPS or stripped or older OTP builds. This issue affects jose: from 1.2.0 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

How to fix CVE-2026-65625

  • No stored fix

    No vendor fix text is stored. Use the linked advisory before you change production.

  • Version check

    Seen in 1.11.10-1 · 8 other packages on the advisory

  • Advisory

    Open the cve_org record and follow its fix.

  • Official advisories

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-2026-65625. EPSS is 0.11%. Act only if a listed version of The pure-Erlang AES-GCM fallback 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. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.11%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Code

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

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 26, 2026 · Trivy Vulnerability DB

    Detected

    The pure-Erlang AES-GCM fallback in jose_jwa_aes derives the number of verified authentication tag bits from the attacker-supplied tag itself. In the {aes_gcm, Bits} clause of block_decrypt/4, the incoming tag is guarded only by is_binary/1, with no check on its length. Verification in gcm_block_decrypt/6 then computes TBits = bit_size(T) and compares only those bits of the real 128-bit tag. An at

  2. Oct 27, 2026 · Trivy Vulnerability DB

    Updated

    The pure-Erlang AES-GCM fallback in jose_jwa_aes derives the number of verified authentication tag bits from the attacker-supplied tag itself. In the {aes_gcm, Bits} clause of block_decrypt/4, the incoming tag is guarded only by is_binary/1, with no check on its length. Verification in gcm_block_decrypt/6 then computes TBits = bit_size(T) and compares only those bits of the real 128-bit tag. An at

Sources

  • CVE.orgVulnerability recordCVE-2026-65625

    Official CVE identifier

    cve.org
  • Trivy Vulnerability DBPackage advisoryDEBIAN-CVE-2026-65625

    The pure-Erlang AES-GCM fallback in jose_jwa_aes derives the number of verified authentication tag bits from the attacker-supplied tag itself. In the {aes_gcm, Bits} clause of block_decrypt/4, the incoming tag is guarded only by is_binary/1, with no check on its length. Verificat

    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.

  • CVE.orgOct 27, 2026
  • Trivy Vulnerability DBOct 27, 2026