---
cve: "CVE-2026-77267"
severity: "HIGH"
cvss: 8.3
epss: "0.6%"
vendor: "sooperset"
kev: false
exploited: false
published: "2026-09-22 18:17:18"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-24T11:19:17+02:00"
---

# CVE-2026-77267

> 8.3 HIGH · 🧪 PoC

## Beschreibung

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the X-Atlassian-Jira-Url and X-Atlassian-Confluence-Url headers are processed by _process_authentication_headers and used to construct Atlassian fetchers without calling validate_url_for_ssrf. A caller who can set these headers can supply an internal or metadata-service URL and cause the server to send requests to that destination, bypassing the incomplete CVE-2026-27826 remediation. This issue is fixed in version 0.22.0.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- b041733473f95119dd539542a43c280737a8e460 (Commit)

## Referenzen

- <https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-5wf4-jqxh-8gm3>
- <https://github.com/sooperset/mcp-atlassian/pull/1448>
- <https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460>
- <https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-77267) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_