CVE-2026-8763

Name Constraints bypass via trailing dot in rfc822Name and URI

Published Aug 3, 2026 CVSS 4.0 · 9.3 Critical EPSS < 1% KEV · Not listed
Description
In Bouncy Castle for Java before 1.85, Name Constraints bypass via trailing dot in rfc822Name and URI. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 1.0.2.7 (1.0.X series), 2.0.2 (2.0.X series) and 2.1.3 (2.1.X series).

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-9pwp-9qqc-pr26 Bouncy Castle: Name Constraints bypass via trailing dot in rfc822Name and URI
History
Type Values Removed Values Added
First Time appeared Bouncycastle
Bouncycastle bc-java
Bouncycastle bouncy Castle For Java Lts
Bouncycastle fips Java Api
CPEs cpe:2.3:a:bouncycastle:bc-java:*:*:*:*:*:*:*:*
cpe:2.3:a:bouncycastle:bouncy_castle_for_java_lts:*:*:*:*:*:*:*:*
cpe:2.3:a:bouncycastle:fips_java_api:*:*:*:*:*:*:*:*
Vendors & Products Bouncycastle
Bouncycastle bc-java
Bouncycastle bouncy Castle For Java Lts
Bouncycastle fips Java Api
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

Type Values Removed Values Added
First Time appeared Legion Of The Bouncy Castle Inc.
Legion Of The Bouncy Castle Inc. bc-fja
Legion Of The Bouncy Castle Inc. bc-java
Legion Of The Bouncy Castle Inc. bc-lts-java
Vendors & Products Legion Of The Bouncy Castle Inc.
Legion Of The Bouncy Castle Inc. bc-fja
Legion Of The Bouncy Castle Inc. bc-java
Legion Of The Bouncy Castle Inc. bc-lts-java
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description In Bouncy Castle for Java before 1.85, Name Constraints bypass via trailing dot in rfc822Name and URI. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 1.0.2.7 (1.0.X series), 2.0.2 (2.0.X series) and 2.1.3 (2.1.X series).
Title Name Constraints bypass via trailing dot in rfc822Name and URI
Weaknesses CWE-295
References
Metrics cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
bcorg
Published
Updated
Oct 5, 2026, 1:16 AM
Reserved
May 17, 2026, 6:03 AM
Status
Analyzed
Published
Aug 3, 2026, 1:16 AM
Modified
Sep 2, 2026, 2:28 PM