# Bouncy Castle: Name Constraints bypass via trailing dot in rfc822Name and URI

Advisory record · `GHSA-9pwp-9qqc-pr26`

- **Identifiers:** `GHSA-9pwp-9qqc-pr26` · `CVE-2026-8763`
- **State:** Confirmed
- **Severity:** CVSS 9.3 Critical
- **Critical:** Yes: CVSS 9+
- **Weakness (CWE):** [CWE-295](https://cwe.mitre.org/data/definitions/295.html)
- **Tags:** [Weak cryptography or TLS](https://agentprime.io/advisories/tag/weak-crypto.md)
- **Published:** 3 Aug 2026
- **Updated:** 18 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 3 Aug 2026, 03:31 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Critical

Critical, because:

- CVSS score 9.3: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected packages

- `org.bouncycastle:bc-fips` (Maven): affected `<1.0.2.7 || >=2.0.0, <2.0.2 || >=2.1.0, <2.1.3`; fixed in `1.0.2.7`, `2.0.2`, `2.1.3`
- `org.bouncycastle:bcprov-jdk18on` (Maven): affected `<1.85`; fixed in `1.85`
- `org.bouncycastle:bcprov-lts8on` (Maven): affected `<2.73.12`; fixed in `2.73.12`
- `org.bouncycastle:bcprov-jdk15to18` (Maven): affected `<1.85`; fixed in `1.85`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 9.3 Critical, CVSS 4.0: `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`, from CNA (bcorg)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0043, the 37th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:16 UTC: First seen by agentprime
- 31 Oct 2026, 14:16 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-9pwp-9qqc-pr26)

## Sources

- [GitHub Advisory Database: GHSA-9pwp-9qqc-pr26](https://github.com/advisories/GHSA-9pwp-9qqc-pr26)
- [OSV: GHSA-9pwp-9qqc-pr26](https://osv.dev/vulnerability/GHSA-9pwp-9qqc-pr26)
- <https://nvd.nist.gov/vuln/detail/CVE-2026-8763>
- <https://github.com/bcgit/bc-java/commit/2c28b253a44681fbbc562561eab6ad383d2ae558>
- <https://github.com/bcgit/bc-java>
- <https://github.com/bcgit/bc-java/releases/tag/r1rv85v2>
- <https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%908763>
- <https://github.com/bcgit/bc-java/wiki/CVE-2026-8763>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-9pwp-9qqc-pr26>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-9pwp-9qqc-pr26/>. Everything for agents: <https://agentprime.io/llms.txt>.