Answer in brief
CVE-2026-71889 records a High severity (CVSS 8.7) vulnerability in PKIXCertPathReviewer does not apply X.509 name constraints to the target certificate. The current sources do not mark it as known exploited. The current feed maps Legion of the Bouncy Castle Inc./bcpkix (generic), Legion of the Bouncy Castle Inc./bcpkix-fips (generic), Legion of the Bouncy Castle Inc./bcpkix-lts8on (generic), Legion of the Bouncy Castle Inc./bcprov (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Legion of the Bouncy Castle Inc./bcpkix (generic), Legion of the Bouncy Castle Inc./bcpkix-fips (generic), Legion of the Bouncy Castle Inc./bcpkix-lts8on (generic), Legion of the Bouncy Castle Inc./bcprov (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Legion of the Bouncy Castle Inc./bcpkixgeneric | >=0 <1.86 | 1.86 |
| Legion of the Bouncy Castle Inc./bcpkix-fipsgeneric | >=1.0.4 <1.0.13 || >=2.0.0 <2.0.13 || >=2.1.0 <2.1.13 | 1.0.13, 2.0.13, 2.1.13 |
| Legion of the Bouncy Castle Inc./bcpkix-lts8ongeneric | >=2.73.0 <2.73.13 | 2.73.13 |
| Legion of the Bouncy Castle Inc./bcprovgeneric | >=0 <1.86 | 1.86 |
Published upstream
Oct 3, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 3, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 3, 2026
In Bouncy Castle for Java before 1.86, neither copy of PKIXCertPathReviewer - org.bouncycastle.pkix.jcajce.PKIXCertPathReviewer nor the legacy org.bouncycastle.x509.PKIXCertPathReviewer - applied X.509 name constraints to the end-entity certificate. checkNameConstraints walked the path with a loop bound of index greater than zero, which is the bound the CA-only steps require, but index zero is the target certificate under the standard CertPath ordering, so the permitted and excluded subtree checks of RFC 5280 sec. 6.1.3 (b) and (c) never ran against the leaf's subject DN or its subjectAltName. A chain whose leaf violated a NameConstraints extension imposed by its own issuing CA therefore reported isValidCertPath() true with an empty error list, while CertPathValidator.getInstance("PKIX", "BC"), which shares no code with the reviewer, rejected the identical chain against the identical trust anchor. An application using the reviewer to make the trust decision rather than for diagnostics alongside a real validation accepted a certificate the constrained CA was never authorised to issue. Both copies now check every certificate in the path including the target, waive the sec. 4.2.1.10 self-issued exemption for the final certificate as sec. 6.1.3 requires, and skip the sec. 6.1.4 (g) constraint-accumulation step for the target. This issue also affects Bouncy Castle for Java LTS before 2.73.13, which carries only the org.bouncycastle.pkix.jcajce copy of the reviewer. It also affects Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series).
Quoted source text, attributed separately from HOL analysis.