In Bouncy Castle for Java before 1.86, NTRU reduced secret values with the % operator in three helpers whose reference implementations are deliberately division-free, so each reduction was carried out by an integer division whose latency depends on the secret operand. Polynomial.modQ divided by a variable divisor, which a compiler cannot strength-reduce to a multiply the way it can a constant one, so it emitted a division on every call including on the decapsulation path where the dividend derives from the private key; Polynomial.mod3 and NTRUSampling.mod3 divided the secret key polynomials f and g during key generation, the message polynomials r and m during encapsulation, and coefficients recovered during decapsulation. An attacker able to measure that timing can recover information about the NTRU private key. modQ now masks, which is exact because q is always a power of two, and mod3 uses the reference implementation's division-free fold and select; the results are unchanged.

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 version of Atlassian Jira Service Management Data Center and Server (Jira Service Desk) running on the remote host is affected by a vulnerability as referenced in the JSDSERVER-16831 advisory.

  - In Bouncy Castle for Java before 1.86, NTRU reduced secret values with the % operator in three helpers     whose reference implementations are deliberately division-free, so each reduction was carried out by an     integer division whose latency depends on the secret operand. Polynomial.modQ divided by a variable     divisor, which a compiler cannot strength-reduce to a multiply the way it can a constant one, so it     emitted a division on every call including on the decapsulation path where the dividend derives from the     private key; Polynomial.mod3 and NTRUSampling.mod3 divided the secret key polynomials f and g during key     generation, the message polynomials r and m during encapsulation, and coefficients recovered during     decapsulation. An attacker able to measure that timing can recover information about the NTRU private key.
    modQ now masks, which is exact because q is always a power of two, and mod3 uses the reference     implementation's division-free fold and select; the results are unchanged. (CVE-2026-18036)

Note that Nessus has not tested for this issue 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, NTRU reduced secret values with the % operator in three helpers     whose reference implementations are deliberately division-free, so each reduction was carried out by an     integer division whose latency depends on the secret operand. Polynomial.modQ divided by a variable     divisor, which a compiler cannot strength-reduce to a multiply the way it can a constant one, so it     emitted a division on every call including on the decapsulation path where the dividend derives from the     private key; Polynomial.mod3 and NTRUSampling.mod3 divided the secret key polynomials f and g during key     generation, the message polynomials r and m during encapsulation, and coefficients recovered during     decapsulation. An attacker able to measure that timing can recover information about the NTRU private key.
    modQ now masks, which is exact because q is always a power of two, and mod3 uses the reference     implementation's division-free fold and select; the results are unchanged. (CVE-2026-18036)

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
367869	Atlassian Jira Service Management Data Center and Server < 10.3.13 / 10.4.x < 11.1.1 (JSDSERVER-16831)	Nessus	Misc.	Local	high
362723	Linux Distros Unpatched Vulnerability : CVE-2026-18036	Nessus	Misc.	Local	high

Detections

Analytics

CVE-2026-18036

high

Tenable Plugins

critical

high

high