CVE-2026-8763

9.3 CRITICAL 0.4% exploit odds Fix listed Crypto

What it is

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).

At a glance

Exploitability: Can be exploited over the network without logging in. High risk of data exposure, data tampering.
Exploit odds: 0.4% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-08-03 01:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-09-02 14:28 UTC Last updatedMost recent change to the record

Details

Published: 2026-08-03 01:16 UTC
Last modified: 2026-09-02 14:28 UTC
Exploit probability: 0.4% · EPSS, next 30 days
Weakness: CWE-295 · Improper certificate validation
Record status: Analyzed

Affected

Bouncycastle bc-java < 1.85
Bouncycastle Bouncy Castle For Java Lts ≤ 2.73.11
Bouncycastle Fips Java Api < 1.0.2.7
Bouncycastle Fips Java Api < 2.0.2
Bouncycastle Fips Java Api < 2.1.3

Attack profile CVSS 4.0 · 9.3

Attack vector: Network
Complexity: Low
Attack requirements: None
Privileges needed: None
User interaction: None
Confidentiality: High
Integrity: High
Availability: None

Raw 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber

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Fix and advisories

References

NVD record · CVE.org record