Bug 2545497 (CVE-2026-71889)
| Summary: | CVE-2026-71889 org.bouncycastle/bcpkix-jdk18on: org.bouncycastle/bcpkix-fips: org.bouncycastle/bcpkix-jdk15on: org.bouncycastle/bcpkix-lts8on: bouncycastle: Bouncy Castle: Certificate validation bypass via missing name constraint checks | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | high | Docs Contact: | |
| Priority: | high | ||
| Version: | unspecified | CC: | amctagga, anthomas, ant, anujha, aoconnor, aschwart, asoldano, aszczucz, ataylor, bbaranow, bmaxwell, bniver, boliveir, bstansbe, cescoffi, csuconic, dbruscin, dfreiber, dlofthou, drichtar, drow, dschmidt, ehelms, ehugonne, ewittman, flucifre, fmariani, fmongiar, gbenhaim, ggainey, gmalinko, gmeno, groman, gsmet, gtanzill, gtully, ikhan, istudens, ivassile, iweiss, janstey, jburrell, jbuscemi, jlanda, jmartisk, jnethert, jpasqual, jsherman, juwatts, jwon, kshier, kvanderr, manderse, mbenjamin, mcarlett, mdellweg, mhackett, mhulan, mosmerov, mposolda, msvehla, nipatil, niyer, nmoumoul, nwallace, olubyans, osousa, ozzy, pantinor, pberan, pcreech, pdelbell, pesilva, pjindal, pmackay, rbobbitt, rchan, rgemmell, rgodfrey, rguimara, rhel-process-autobot, rkubis, rmartinc, rstancel, rstepani, sbiarozk, sdawley, simaishi, smallamp, sostapov, ssilvert, stcannon, sthorger, tbish, tcunning, thjenkin, tlavocat, tmalecek, twaugh, varjain, vdosoudi, vereddy, vkumar, vmuzikar, watson-tool-maintainers, yfang, yguenane |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in Bouncy Castle. The certificate path reviewer (PKIXCertPathReviewer) fails to enforce name constraints on the end-entity certificate during validation. A remote attacker can exploit this issue by presenting a certificate that violates domain restrictions imposed by an issuing Certificate Authority (CA). Applications that rely on the reviewer to determine trust may incorrectly accept unauthorized certificates as valid.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 2552393, 2552398, 2552399, 2552403, 2552406, 2552407, 2552408, 2552410, 2552391, 2552397, 2552400, 2552404 | ||
| Bug Blocks: | |||
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).