OpenPGP AEAD Decryption Vulnerability in Bouncy Castle for Java
CVE-2026-12817

8.7HIGH

Key Information:

Vendor

Legion Of The Bouncy Castle Inc.

Status
Bc-java
Bc-lts-java
Bc-fja
Vendor
CVE Published:
3 August 2026

What is CVE-2026-12817?

A flaw in Bouncy Castle for Java prior to version 1.85 and in specific LTS and FIPS versions allows for the final tag to be skipped during OpenPGP AEAD decryption on chunk-aligned data. This could potentially lead to unauthorized access or manipulation of sensitive information. Users and developers are urged to update to the latest versions to mitigate this vulnerability.

Affected Version(s)

BC-FJA all 1.0.7 < 1.0.13

BC-FJA all 2.0.0 < 2.0.13

BC-FJA all 2.1.0 < 2.1.13

References

https://github.com/bcgit/bc-java/wiki/CVE-2026-12817
vendor-advisory
https://github.com/bcgit/bc-java/commit/4b712819846ec9443...
patch

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Alex Gaynor in collaboration with Claude and Anthropic Research
.