Executive brief
Bouncy Castle is a cryptographic library used by Java applications to implement encryption and digital signatures. This vulnerability causes OpenPGP inline-signature policy checks to fail silently, allowing digitally signed messages that should be rejected to be accepted without warning. An attacker could forge or manipulate signed messages that appear valid to applications relying on signature verification.
Technical details
The vulnerability exists in Bouncy Castle's OpenPGP inline-signature policy validation logic, where policy failures are silently ignored rather than raising an exception or returning a failure status. This affects the bcpg component responsible for OpenPGP message processing. The vulnerability is present in Bouncy Castle for Java before version 1.85 and in the FIPS-validated variant (BC-FJA) before bcpg-fips 2.0.13. An attacker can exploit this by crafting OpenPGP messages with invalid inline signatures that bypass policy checks, potentially leading to acceptance of forged or tampered signed content. Applications using affected versions must upgrade to patched releases.
Affected products
- Bouncycastle Bouncy Castle for Java before 1.85
- Bouncycastle Bouncy Castle for Java FIPS before bcpg-fips 2.0.13
Timeline
- 2026-08-03: disclosed