CVE-2026-59638
JSSE hostname verifier CN-fallback enabled by default despite documented opt-in
CRITICAL 9.3
At a glance
- Source
- NVD
- EPSS
- EPSS 0.34 % · percentile 28 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- bcorg
- NVD status
- Analyzed
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).
Weaknesses (CWE)
- CWE-297 — Improper Validation of Certificate with Host Mismatch
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | CRITICAL 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 | bcorg |
| CVSS 4.0 | CRITICAL 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber | NVD · 91579145-5d7b-4cc5-b925-a0262ff19630 (Secondary) |
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2026-52016
- GCVE · GCVE-0-2026-59638
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1336 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1291 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1256 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:bouncycastle:bc-java:*:*:*:*:*:*:*:*< 1.85cpe:2.3:a:bouncycastle:bctls-fips:*:*:*:*:*:*:*:*≥ 1.0.0 < 1.0.24cpe:2.3:a:bouncycastle:bctls-fips:*:*:*:*:*:*:*:*≥ 2.0.19 < 2.0.24cpe:2.3:a:bouncycastle:bctls-fips:*:*:*:*:*:*:*:*≥ 2.1.20 < 2.1.24cpe:2.3:a:bouncycastle:bouncy_castle_for_java_lts:*:*:*:*:*:*:*:*≤ 2.73.11
Affected products
| Product | Versions |
|---|---|
| Legion of the Bouncy Castle Inc. · BC-JAVA | affected 1.61 < 1.85 |
| Legion of the Bouncy Castle Inc. · BC-LTS-JAVA | affected 2.73.0 < 2.73.12 |
| Legion of the Bouncy Castle Inc. · BC-FJA | affected 1.0.7 < 1.0.24 ; affected 2.0.0 < 2.0.24 ; affected 2.1.0 < 2.1.24 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |