CVE-2026-59638criticalCWE-297

CVE-2026-59638: critical vulnerability in Legion of the Bouncy Castle Inc. BC-FJA

JSSE hostname verifier CN-fallback enabled by default despite documented opt-in

Published

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28Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 9.3epss 0.3%
In Bouncy Castle for Java before 1.85, JSSE hostname verifier CN-fallback enabled by default despite documented opt-in. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bctls-fips 1.0.24 (1.0.X series), 2.0.24 (2.0.X series) and 2.1.24 (2.1.X series).
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber
Affected products
Legion of the Bouncy Castle Inc. · BC-FJALegion of the Bouncy Castle Inc. · BC-JAVALegion of the Bouncy Castle Inc. · BC-LTS-JAVA
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