p PatchFirst

CVE-2026-17508

CVE-2026-17508 · Password-based KDF cost parameters honoured unbounded from untrusted input across the remaining PBE entry points

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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).

CVSS 5.3 · Medium · EPSS 0.4% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • bc-java

    Versions
    • ≥ 0, < 1.86: Affected (maven)

    Update to 1.86

  • bc-lts-java

    Versions
    • ≥ 2.73.0, < 2.73.13: Affected (maven)

    Update to 2.73.13

  • bc-fja

    Versions
    • ≥ 1.0.0, < 1.0.13: Affected (maven)
    • ≥ 2.0.0, < 2.0.13: Affected (maven)
    • ≥ 2.1.0, < 2.1.13: Affected (maven)

    Update to 1.0.13; Update to 2.0.13; Update to 2.1.13

  • bouncycastle Debian:12

    Versions
    • 1.72-2
    • 1.77-1
    • 1.80-1
    • 1.80-2
    • 1.80-3
    • 1.86-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bouncycastle Debian:13

    Versions
    • 1.80-3
    • 1.86-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bouncycastle Debian:14

    Versions
    • 1.80-3
    Affected ranges
    • ECOSYSTEM: < 1.86-1

    Update to 1.86-1

  • bouncycastle Ubuntu:Pro:16.04:LTS

    Versions
    • 1.49+dfsg-3ubuntu1
    • 1.51-4ubuntu1
    • 1.51-4ubuntu1+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bouncycastle Ubuntu:Pro:18.04:LTS

    Versions
    • 1.57-1
    • 1.58-1
    • 1.59-1
    • 1.59-1ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bouncycastle Ubuntu:Pro:20.04:LTS

    Versions
    • 1.61-1
    • 1.61-1ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bouncycastle Ubuntu:Pro:22.04:LTS

    Versions
    • 1.68-2
    • 1.68-4
    • 1.68-5
    • 1.68-5ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bouncycastle Ubuntu:Pro:24.04:LTS

    Versions
    • 1.72-2
    • 1.77-1
    • 1.77-1ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bouncycastle Ubuntu:26.10

    Versions
    • 1.80-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bouncycastle Ubuntu:26.04:LTS

    Versions
    • 1.80-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

Check your server →