{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-71889 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2026-71889 is a high-severity vulnerability in Legion of the Bouncy Castle Inc. BC-FJA, published on 3 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-71889 and fix it if it is affected.\n\nWhat it is: CVE-2026-71889 is a high-severity vulnerability in Legion of the Bouncy Castle Inc. BC-FJA, published on 3 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-71889 in the wild and no public exploit code.\n\nAffected product: Legion of the Bouncy Castle Inc. BC-FJA. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-71889/ (Markdown: https://insights.sbomify.com/CVE-2026-71889/index.md)","id":"CVE-2026-71889","markdown":"https://insights.sbomify.com/CVE-2026-71889/index.md","name":"CVE-2026-71889","record":{"aliases":["CLEANSTART-2026-JL85698","CLEANSTART-2026-LI97281","DEBIAN-CVE-2026-71889","GHSA-hqqj-v58h-gr7x","ROOT-APP-MAVEN-CVE-2026-71889","UBUNTU-CVE-2026-71889"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Java cryptography library","requires_auth":"none","summary":"Attackers can bypass X.509 name constraints in Bouncy Castle Java, causing the library to incorrectly validate certificates that violate CA restrictions.","user_interaction":"not_required","vuln_class":"security_feature_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"bcorg","cpe":[],"cvss":{"score":8.7,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber","version":"4.0"},"cwes":[{"id":"CWE-295","name":"Improper Certificate Validation"}],"description":"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).","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"PKIXCertPathReviewer does not apply X.509 name constraints to the target certificate","id":"CVE-2026-71889","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"security_feature_bypass","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"MLS external commit can remove an arbitrary group member","id":"CVE-2026-71890"},"packages":[],"prev":{"headline":"CMS AuthenticatedData exposes attacker-inserted authAttrs when digestAlgorithm is absent","id":"CVE-2026-71888"},"products":["BC-FJA","BC-JAVA","BC-LTS-JAVA"],"published":"2026-10-03","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-05","vendors":["Legion of the Bouncy Castle Inc."]},"summary":"Attackers can bypass X.509 name constraints in Bouncy Castle Java, causing the library to incorrectly validate certificates that violate CA restrictions.","url":"https://insights.sbomify.com/CVE-2026-71889/"}