by Kastro
Paper/Archive/CVE-2026-8763

CVE-2026-8763

Legion of the Bouncy Castle Inc. BC-JAVA — Name Constraints bypass via trailing dot in rfc822Name and URI

EPSS 0.4%CVSS 9.3
critical.is priorityof 100
35
CVSS 9.3 (CNA)9.3 / 10 × 3027.9Not in CISA KEV+300.0EPSS percentile 37.2.372 × 207.4No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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).

Affected

ProductAffectedFixed inSource
BC-JAVA< 1.851.85CNA
BC-LTS-JAVA2.73.0 – < 2.73.122.73.12CNA
BC-FJA1.0.0 – < 1.0.2.71.0.2.7CNA
BC-FJA2.0.0 – < 2.0.22.0.2CNA
BC-FJA2.1.0 – < 2.1.32.1.3CNA

Scores by source

bcorg (CNA)9.3CVSS: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
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

advisorygithub.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%908763patchgithub.com/bcgit/bc-java/commit/2c28b253a44681fbbc562561eab6ad383d2ae558