cyfenced.com →

[ CVE-2026-17508 · Published 2 Oct 2026 ]

Vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA

CVSS 5.3 EPSS <1%2 agency advisoriesNo fix listed yet

[ Description ]Official description

In Bouncy Castle for Java before 1.86, several password-based key derivation entry points ran the KDF with cost parameters taken from the untrusted input being processed, without bounding them, so a small input could dictate an arbitrary amount of work before any password or integrity check could reject it. The affected paths are the RFC 9579 PBMAC1 MAC calculator builders, which took the PBKDF2 iteration count and derived-key length straight out of PBMAC1Params (JcePBMac1CalculatorBuilder, and PKCS12PBEUtils.createPBMac1Calculator reached from PKCS12PfxPdu.isMacValid); the scrypt parallelization parameter p in the PKCS#8 and PKCS#12 cost guards, which bounded only the cost parameter N and the block size r even though the scratch buffer scales with r times p, so the configured memory ceiling could be evaded entirely; the raw JCA PBKDF2 provider (org.bouncycastle.jcajce.provider.symmetric.PBEPBKDF2); and the bcrypt round count read from an encrypted OpenSSH v1 private key's own kdfoptions. Each now bounds the parameter before deriving, in line with the caps already applied elsewhere in the tree, with the OpenSSH round count configurable through the new org.bouncycastle.openssh.max_rounds property. This completes the bounding begun in 1.85 for the PKCS#8 / PBES2 decryptors (CVE-2026-15055). This issue also affects Bouncy Castle for Java LTS before 2.73.13, and 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).

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

  • CERT-FRCERTFR-2026-AVI-1336

    Multiple vulnerabilities in IBM products Translated from French

    Multiple vulnerabilities have been discovered in IBM products. Some of them allow an attacker to cause remote arbitrary code execution, privilege escalation and remote denial of service.

    CVE-2026-14671CVE-2026-11548CVE-2022-22950+490 more CVEs
  • BSI CERT-BundWID-SEC-2026-3713

    Bouncy Castle: Multiple vulnerabilities Translated from German

    Risk mediumCVE-2026-63575CVE-2026-63570CVE-2026-63577+19 more CVEs

[ References ]References