CVE-2026-12185: BKS/UBER keystore allocates from untrusted lengths before integrity check

Severity: high (CVSS 8.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-03 · updated 2026-08-28
Weakness: CWE-789

Description

In Bouncy Castle for Java before 1.85, BKS/UBER keystore allocates from untrusted lengths before integrity check. This issue also affects Bouncy Castle for Java LTS before 2.73.12.

Affected products

Legion of the Bouncy Castle Inc. BC-JAVA: before 1.85 — fixed in 1.85
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. Check the vendor advisory for mitigations.

References

https://github.com/bcgit/bc-java/commit/7bbd7fe5f44132e5b6140a2914435c12430eeb3d
https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9012185

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