CVE-2026-12860
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk8th percentile - higher than 8% of all known CVEs
Summary
In Bouncy Castle for Java before 1.85, RSA PKCS#1 signature verification skips the last two hash bytes in the NULL-omitted path. This issue also affects LTS before 2.73.12.
Risk Assessment
An attacker could forge an RSA signature for some messages, as verification may accept an invalid signature due to the omission of the last hash bytes.
Recommendation
Upgrade Bouncy Castle to version 1.85 or later (for the regular version) and to 2.73.12 or later (for LTS).
Other vulnerabilities in Bouncy Castle
See all- CVE-2026-58062Critical
In Bouncy Castle for Java before 1.85, a Stapled OCSP response is accepted without binding to the checked certificate. This issue also affects LTS before 2.73.12 and FIPS before 2.0.2 (2.0.X series) and 2.1.3 (2.1.X series).
- CVE-2026-8763Critical
In Bouncy Castle for Java before 1.85, Name Constraints can be bypassed via a trailing dot in rfc822Name and URI. This issue also affects LTS before 2.73.12 and FIPS before appropriate versions.
- CVE-2026-59650Critical
In Bouncy Castle for Java before 1.85, the MTI/A0 Diffie-Hellman key agreement exponentiates an unvalidated peer value. This issue also affects LTS before 2.73.12.
- CVE-2026-14682High
In Bouncy Castle for Java before 1.85, a possible Out-of-Memory (OOM) condition exists due to unbounded up-front allocation on a definite-length read. This issue also affects LTS and FIPS versions.
- CVE-2026-13586High
In Bouncy Castle for Java before 1.85, the PKCS#12 MAC and bag-decryption KDF iteration-count bound can lead to DoS. This issue also affects LTS before 2.73.12 and BC-FJA before specific versions.
- CVE-2026-13506High
In Bouncy Castle for Java before 1.85, a Lazy ASN.1 sequence forces resetting the nesting-depth guard. This issue also affects LTS and FIPS versions.
- CVE-2026-12852High
In Bouncy Castle for Java before 1.85, the MLS wire decoder allocates attacker-declared opaque length before bounds check.
- CVE-2026-12817High
In Bouncy Castle for Java before 1.85, OpenPGP AEAD decryption skips the final tag on chunk-aligned data. This issue also affects LTS and FIPS versions.
- CVE-2026-12816High
In Bouncy Castle for Java before 1.85, the IESEngine in stream mode allows MAC forgery via length-dependent KDF split. This issue also affects LTS before 2.73.12.
- CVE-2026-12803High
In Bouncy Castle for Java before 1.85, the KCCMBlockCipher MAC does not bind the nonce when AAD is absent, allowing cross-nonce AEAD forgery. This also affects Bouncy Castle for Java LTS before 2.73.12.
Original NVD description (English source)
In Bouncy Castle for Java before 1.85, RSA PKCS#1 verification skips last two hash bytes in NULL-omitted path. This issue also affects Bouncy Castle for Java LTS before 2.73.12.