CVE-2026-59638
Low
No strong exploitation signal.
CVSS base
6.5
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS — probability of exploitation (30 days)
0.2%
11.6th percentile
CISA KEV
Not listed
Weakness / dates
CWE-297
Published 2026-08-03 · modified 2026-08-28
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | L | Low |
| Integrity | L | Low |
| Availability | N | None |
Timeline
- 2026-08-03 — Published (NVD)
- 2026-08-28 — Last modified (NVD)
Description
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).