What’s Vulnerable › Vulnerabilities

CVE-2026-12802: CMS AuthEnvelopedData fails to enforce tag-length on decryption

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-03 · updated 2026-09-02
• Weakness: CWE-354

Description

In Bouncy Castle for Java before 1.85, CMS AuthEnvelopedData fails to enforce tag-length on decryption. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.12 (1.0.X series), 2.0.12 (2.0.X series) and 2.1.12 (2.1.X series).

Affected products

• Legion of the Bouncy Castle Inc. BC-JAVA: before 1.85 — fixed in 1.85
• Legion of the Bouncy Castle Inc. BCPKIX-FIPS: before 1.0.12; from 2.0.7 before 2.0.12; from 2.1.8 before 2.1.12 — fixed in 1.0.12, 2.0.12, 2.1.12
• Legion of the Bouncy Castle Inc. Bouncy Castle for Java LTS: through 2.73.11

How to fix

Upgrade to a fixed version: Legion of the Bouncy Castle Inc. BC-JAVA 1.85; Legion of the Bouncy Castle Inc. BCPKIX-FIPS 1.0.12, 2.0.12, 2.1.12. Check the vendor advisory for mitigations.

References

• https://github.com/bcgit/bc-java/commit/0fefa539e6ac5c66e1daee5a13b23d1d4769cc01
• https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9012802

Get alerted when CVE-2026-12802 or the next vulnerability affects your stack