TI-2026-42545 Aliases CVE-2026-59650 GHSA-ghgq-7g74-28wp

MTI/A0 DH agreement exponentiates unvalidated peer value

MEDIUM 48CWE-20Published 2026-08-03 · Updated 2026-08-03

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: —
Confidentiality · integrity · availability: High · High · None
Fix status: Partial Red Hat: 1 fixed, 12 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat.

Summary

In Bouncy Castle for Java before 1.85, MTI/A0 DH agreement exponentiates unvalidated peer value. This issue also affects Bouncy Castle for Java LTS before 2.73.12.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00337 27th percentileScored 2026-11-07

Fix Partial BC-JAVA (Legion of the Bouncy Castle Inc.): 1.85BC-LTS-JAVA (Legion of the Bouncy Castle Inc.): 2.73.12Red Hat: 1 advisoryRed Hat: 1 fixed, 12 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Legion of the Bouncy Castle Inc.	BC-JAVA	before 1.85	1.85	Patch available	CNA
Legion of the Bouncy Castle Inc.	BC-LTS-JAVA	2.73.0 to before 2.73.12	2.73.12	Patch available	CNA

BC-JAVA VendorLegion of the Bouncy Castle Inc. Affected before 1.85 Fixed in 1.85 Patch available CNA
BC-LTS-JAVA VendorLegion of the Bouncy Castle Inc. Affected 2.73.0 to before 2.73.12 Fixed in 2.73.12 Patch available CNA

CPE configurations NVD · 2

CPE	Versions	Role	Vendor
cpe:2.3:a:bouncycastle:bc-java::::::::	before 1.85	Vulnerable	Legion of the Bouncy Castle Inc.
cpe:2.3:a:bouncycastle:bouncy_castle_for_java_lts::::::::	up to 2.73.11	Vulnerable	Legion of the Bouncy Castle Inc.

cpe:2.3:a:bouncycastle:bc-java:*:*:*:*:*:*:*:* Versions before 1.85 Vulnerable ·Legion of the Bouncy Castle Inc.
cpe:2.3:a:bouncycastle:bouncy_castle_for_java_lts:*:*:*:*:*:*:*:* Versions up to 2.73.11 Vulnerable ·Legion of the Bouncy Castle Inc.

Remediation

Fix · CNA BC-JAVA (Legion of the Bouncy Castle Inc.) Fixed in 1.85
Fix · CNA BC-LTS-JAVA (Legion of the Bouncy Castle Inc.) Fixed in 2.73.12

Red Hat 1 advisory

RHSA-2026:95887 Released 2026-11-06 · Red Hat rating Important
Red Hat JBoss Enterprise Application Platform 8.1.9 security update
- Red Hat JBoss Enterprise Application Platform 8.1

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Release · 2026-08-03
Legion of the Bouncy Castle BC-JAVA 1.85
32 records Highest priority Priority MEDIUM 23 MEDIUM, 9 LOW
Other records, highest priority first
- TI-2026-42533 JSSE hostname verifier CN-fallback enabled by default despite documented opt-inPriority MEDIUM 48
- TI-2026-41816 Stapled OCSP response accepted without binding to the checked certificatePriority MEDIUM 48
- TI-2026-07701 Name Constraints bypass via trailing dot in rfc822Name and URIPriority MEDIUM 48
Show all 32 records →
Release · 2026-08-03
Legion of the Bouncy Castle BC-LTS-JAVA 2.73.12
28 records Highest priority Priority MEDIUM 20 MEDIUM, 8 LOW
Other records, highest priority first
- TI-2026-42533 JSSE hostname verifier CN-fallback enabled by default despite documented opt-inPriority MEDIUM 48
- TI-2026-41816 Stapled OCSP response accepted without binding to the checked certificatePriority MEDIUM 48
- TI-2026-07701 Name Constraints bypass via trailing dot in rfc822Name and URIPriority MEDIUM 48
Show all 28 records →

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

Product	Status	Plan or fix
OpenShift Developer Tools and Services	Affected	—
Red Hat AMQ Broker 7	Affected	No fix yet
Red Hat Ansible Automation Platform 2	Affected	—
Red Hat Build of Keycloak	Affected	No fix yet
Red Hat Fuse 7	Affected	No fix planned: Out of support scope
Red Hat JBoss Enterprise Application Platform 7	Affected	No fix planned: Will not fix
Red Hat OpenShift AI (RHOAI)	Affected	—
Red Hat OpenShift Dev Spaces	Affected	—
Red Hat Satellite 6	Affected	—
Red Hat Single Sign-On 7	Affected	No fix planned: Out of support scope
Red Hat build of Apache Camel for Spring Boot 4	Affected	No fix yet
Red Hat build of Apicurio Registry 3	Affected	No fix yet
Red Hat JBoss Enterprise Application Platform 8.1	Fixed	RHSA-2026:95887

Not affected: 5 products

Red Hat Enterprise Linux 8
Red Hat Enterprise Linux 9
Red Hat JBoss Enterprise Application Platform Expansion Pack
Red Hat build of Apache Camel 4 for Quarkus 3
Red Hat build of Quarkus

Timeline

2026-10-02 Threatist record created from CVE-2026-59650
2026-10-03 Alias added: GHSA-ghgq-7g74-28wp
2026-11-06 Fix available: RHSA-2026:95887 · Red Hat
2026-11-06 Fix available: Red Hat JBoss Enterprise Application Platform 8.1 · Red Hat

References

Patch 1

https://github.com/bcgit/bc-java/commit/daeaae9d7075d04f40812e68671ebf4c777b5148

Advisory 1

https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059650

TI-2018-15967 Legion of the Bouncy Castle Legion of the Bouncy Castle Java Cryptography APIs 1.58 up to… CVSS 3.1CRITICAL 9.8
TI-2017-09736 BouncyCastle JCE TLS Bleichenbacher/ROBOT CVSS 3.0HIGH 7.5
TI-2026-42533 JSSE hostname verifier CN-fallback enabled by default despite documented opt-in CVSS 4.0CRITICAL 9.3
TI-2026-41816 Stapled OCSP response accepted without binding to the checked certificate CVSS 4.0CRITICAL 9.3
TI-2026-07701 Name Constraints bypass via trailing dot in rfc822Name and URI CVSS 4.0CRITICAL 9.3
TI-2007-06415 The Legion of the Bouncy Castle Java Cryptography API before release 1.38, as used in… CVSS 2.0HIGH 10.0

See all 52 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences