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).

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:4797-1 advisory.

    - CVE-2026-17507: negative signed leaf_index values from unsigned wire encodings can cause heap exhaustion       (bsc#1284075).
    - CVE-2026-17508: unbounded KDF iteration and memory parameters can cause resource exhaustion     (bsc#1284073).
    - CVE-2026-18036: variable-time modulo and division operations in NTRU implementation can allow timing     side-channel       attacks (bsc#1284065).
    - CVE-2026-18040: table lookups and variable-time duplicate scanning in HQC can cause cache side-channel     leaks       (bsc#1284205).
    - CVE-2026-71885: unbound X.509 certificates in MLS LeafNode verification can cause identity impersonation     and group       message interception (bsc#1284165).
    - CVE-2026-71886: unvalidated CERTIFY_OTHER flags in OpenPGP subkeys can cause unauthorized trust     delegations and       identity spoofing (bsc#1284212).
    - CVE-2026-71887: missing primary key back-signature validation on subkeys can cause signature     misattribution and trust       context spoofing (bsc#1284213).
    - CVE-2026-71888: disagreement between digestAlgorithm and authAttrs in CMS parsing can cause     unauthenticated attribute       injection (bsc#1284215).
    - CVE-2026-71889: skipped leaf certificate evaluation in checkNameConstraints can cause X.509 name     constraint bypasses       (bsc#1284218).
    - CVE-2026-71890: unbounded Remove proposals in external MLS commits can cause arbitrary group member     eviction and       session takeover (bsc#1284219).
    - CVE-2026-71891: forged ECPoint curves in BLS12-381 key validation can cause aggregate signature     verification bypasses       (bsc#1284220).
    - CVE-2026-71892: type mismatch in CMS key-transport validation can cause key-size enforcement bypasses     for HKDF-derived       content keys (bsc#1284221).
    - CVE-2026-85515: laundered EOF exceptions in OpenPGP message stream processing can cause unregistered     truncation errors       and integrity check bypasses (bsc#1284222).
    - CVE-2026-97873: unbounded iteration counts in legacy PBES1 and PKCS#12 PBE implementations can cause     resource       exhaustion (bsc#1284224).

    Changes for bouncycastle:

    - Updated to version 1.86.

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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). (CVE-2026-17508)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
370393	SUSE SLED15: bouncycastle / bouncycastle-pg / bouncycastle-pkix / etc (SUSE-SU-2026:4797-1)	Nessus	SuSE Local Security Checks	Local	critical
362780	Linux Distros Unpatched Vulnerability : CVE-2026-17508	Nessus	Misc.	Local	medium

Detections

Analytics

CVE-2026-17508

medium

Tenable Plugins

critical

medium