CVE-2026-59638
9.3
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
Summary
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).
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Legion of the Bouncy Castle Inc. | BC-JAVA | 1.61 < 1.85 | affected |
| Legion of the Bouncy Castle Inc. | BC-LTS-JAVA | 2.73.0 < 2.73.12 | affected |
| Legion of the Bouncy Castle Inc. | BC-FJA | 1.0.7 < 1.0.24 | affected |
| Legion of the Bouncy Castle Inc. | BC-FJA | 2.0.0 < 2.0.24 | affected |
| Legion of the Bouncy Castle Inc. | BC-FJA | 2.1.0 < 2.1.24 | affected |
Weaknesses
- CWE-297: CWE-297 Improper Validation of Certificate with Host Mismatch
References
- https://github.com/bcgit/bc-java/wiki/CVE-2026-59638
- https://github.com/bcgit/bc-java/commit/799bd15320a6310a447863638aa3df64acef829b
- https://github.com/bcgit/bc-java/commit/5ac55351cd1a8a7184d41c96a7ee87df0770240a
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