CVE-2026-12817

High

Description

In Bouncy Castle for Java before 1.85, OpenPGP AEAD decryption skips final tag on chunk-aligned data. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpg-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series).

SeverityHigh

CVSS8.6

Exploit probability—

ProductBouncycastle Bcpg-fips

PublishedAug 3, 2026

First seenAug 3, 2026

Weakness typeCWE-354CWE-354

How to fix

Update

bouncycastle bcpg-fips1.0.13, 2.0.13, 2.1.13 or later
bouncycastle bc-java1.85 or later

Patches

github.com/bcgit/bc-java/commit/4b712819846ec944379f4909101abac20f0ad4b0

Vendor advisories

github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9012817

Affected products

Product	Affected versions	Fixed in
bouncycastle bcpg-fips	1.0.7 ≤ v < 1.0.13, 2.0.8 ≤ v < 2.0.13, 2.1.10 ≤ v < 2.1.13	1.0.13, 2.0.13, 2.1.13
bouncycastle bc-java	v < 1.85	1.85
bouncycastle bouncy_castle_for_java_lts	v ≤ 2.73.11	—

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