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🎯 CVE-2026-21580 HIGH 8.6 🔥 EPSS 36% 🇪🇺 EUVD
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CVE-2026-21580 | This Critical severity Stored XSS, PrivEsc (Privilege Escalation), and Security Misconfiguration vulnerability was introduced in versions 7.1.1, 7.4.0, 7.13.0, 7.17.0, 7.19.0, 8.0.0, 8.5.0, 8.9.0, 9.0.1, 9.1.0, 9.2.0, 9.3.1, 9.4.0, 9.5.1, 10.0.2, 10.1.0 and 10.2.0 of Confluence Data Center and Server. This Stored XSS, PrivEsc (Privilege Escalation), and Security Misconfiguration vulnerability, with a CVSS Score of 8.6, allows an unauthenticated attacker to

This Critical severity Stored XSS, PrivEsc (Privilege Escalation), and Security Misconfiguration vulnerability was introduced in versions 7.1.1, 7.4.0, 7.13.0, 7.17.0, 7.19.0, 8.0.0, 8.5.0, 8.9.0, 9.0.1, 9.1.0, 9.2.0, 9.3.1, 9.4.0, 9.5.1, 10.0.2, 10.1.0 and 10.2.0 of Confluence Data Center and Server.

This Stored XSS, PrivEsc (Privilege Escalation), and Security Misconfiguration vulnerability, with a CVSS Score of 8.6, allows an unauthenticated attacker to execute arbitrary HTML or JavaScript code on a victims browser, perform actions as a higher-privileged user, and to get into the system utilizing loopholes exposed from security best-practices being overlooked.

Atlassian recommends that Confluence Data Center and Server customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions:
Confluence Data Center and Server 9.2: Upgrade to a release greater than or equal to 9.2.21

Confluence Data Center and Server 10.2: Upgrade to a release greater than or equal to 10.2.13

See the release notes ([https://confluence.atlassian.com/doc/confluence-release-notes-327.html]). You can download the latest version of Confluence Data Center and Server from the download center ([https://www.atlassian.com/software/confluence/download-archives]).

This vulnerability was reported via our Bug Bounty program.

Klassifikation & Betroffenheit:
Atlassian Confluence Data Center 10.1.0 to 10.1.2Confluence Data Center 9.3.1 to 9.3.2Confluence Data Center 7.19.27 to 7.19.30Confluence Data Center 9.0.3Confluence Data Center 10.2.0 to 10.2.11Confluence Data Center 8.5.15 to 8.5.31Confluence Data Center 9.4.0 to 9.4.1Confluence Data Center 10.0.2 to 10.0.3
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') 🎯 High

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

🛡️ Empfohlene Mitigation: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482]. Examples of libraries and frameworks that make it easier to generate properly encoded output include Microsoft's Anti-XSS library, the OWASP ESAPI Encoding module, and …
Vollständige Definition bei MITRE ➔
⚔️ Typische Angriffsmuster (CAPEC):
CAPEC-63 · Cross-Site Scripting (XSS) (Very High) CAPEC-85 · AJAX Footprinting (Low) CAPEC-209 · XSS Using MIME Type Mismatch (Medium) CAPEC-588 · DOM-Based XSS (Very High) CAPEC-591 · Reflected XSS (Very High) CAPEC-592 · Stored XSS (Very High)
🧩 Ähnliche Schwachstellen (Hersteller/Klasse/Score-Band):
CVE-2023-22527 10.0 CVE-2023-22518 10.0 CVE-2023-22515 10.0 CVE-2023-22523 9.8 CVE-2022-43782 9.8
📚 Referenzen & Quellen:
🇪🇺 Original-Eintrag (ENISA EUVD) 🇺🇸 NVD-Eintrag
Ausnutzungs-Zeitleiste:
CVSS-Vektor-Analyse: 8.6
AV · Angriffsvektor Netzwerk
AC · Komplexität Gering
PR · Privilegien Keine
UI · Interaktion Keine
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Veröffentlicht:18.08.2026
Aktualisiert:21.08.2026 14:45
Assigner (CNA):atlassian
EUVD-ID:EUVD-2026-62205
CWE-79: Cross-Site Scripting ✓ Offizieller Patch / Advisory verfügbar
💡 Gegenmaßnahme: Sicherheits-Update des Herstellers zeitnah einspielen und Netzwerksegmentierung prüfen.
🔴 Live Security Advisory & EPSS Exploit Radar

Zero-Day & Vulnerability Intelligence Hub

Echtzeit-Tracking mit EPSS Exploit-Wahrscheinlichkeiten, Angriffsvektor-Decodern und KI-Patch-Anleitungen.

🟢 SSE Realtime Synchronisiert ⚡ REST API (JSON) 📡 Digest (RSS) 📡 RSS Feed
354k+ 🇪🇺 EUVD-Datenbank
0 🔴 Critical im Radar
0 ⚠️ CISA KEV
0 🔓 Aktiv ausgenutzt
0 🧪 PoC verfügbar
10 🆕 Neu im KEV (7 T)
📊 Historien-Charts — Criticals-Trend · Vendors · EPSS-Verteilung
🔴 Criticals pro Monat (12 M) 2025-09: 237 2025-10: 316 2025-11: 257 2025-12: 426 2026-01: 431 2026-02: 418 2026-03: 652 2026-04: 574 2026-05: 683 2026-06: 942 2026-07: 1333 2026-08: 1329 7.598 Criticals gesamt
🏢 Top-Vendor-Veröffentlichungen (6 M) Adobe Apple Google Linux Microsoft Oracle Corporation
● Adobe ● Apple ● Google ● Linux ● Microsoft ● Oracle
📈 EPSS-Verteilung (Messungen)
Tier2026-08-292026-09-06
≥90 %40
≥50 %40
≥10 %30
<10 %304300
📈 EPSS-Riser (7 Tage) CVE-2016-4776 ↑ 0.8 % CVE-2016-4773 ↑ 0.8 % CVE-2016-4774 ↑ 0.8 %
Frühindikator · FIRST.org
Datenquellen & Methodik: Primärquelle ist die EUVD der ENISA (laufender Datenbank-Sync, alle 15 Minuten), abgeglichen mit dem CISA-KEV-Katalog und der NVD — Detail-Dossiers reichern fehlende Felder live per NVD an — mit Fallback auf CIRCL vulnerability-lookup (EU/Non-Profit, aggregiert CVE-, GitHub- und OSV-Advisories). Der CISA-KEV-Katalog (Known Exploited Vulnerabilities, ~1.700 aktiv ausgenutzte Schwachstellen) wird bei jedem Sync vollständig neu geladen und kreuzreferenziert — filterbar über die KEV-Pille. CVSS 3.1 wird nach Ampel-Logik aus Verteidigersicht dekodiert; EPSS bezeichnet die 30-Tage-Exploit-Wahrscheinlichkeit (FIRST.org).
🇪🇺 ENISA EUVD 🇺🇸 NVD ⚠️ CISA KEV ⚡ EPSS
Ökosystem & Hersteller Bedrohungs-Matrix:
Atlassian 1
Schweregrad & Status:
Hersteller (Datenbank-weit, 90.597 Einträge):
EPSS-Schwelle:
Quelle:
Schwachstellen-Kategorie (CWE):
🔍
8.6 HIGH
🇪🇺 EUVD
EPSS 36%
CVE-2026-21580 🌐 Netzwerk (Remote) 🔓 Keine Authentifizierung nötig
Atlassian

CVE-2026-21580 | This Critical severity Stored XSS, PrivEsc (Privilege Escalation), and Security Misconfiguration vulnerability was introduced in versions 7.1.1, 7.4.0, 7.13.0, 7.17.0, 7.19.0, 8.0.0, 8.5.0, 8.9.0, 9.0.1, 9.1.0, 9.2.0, 9.3.1, 9.4.0, 9.5.1, 10.0.2, 10.1.0 and 10.2.0 of Confluence Data Center and Server. This Stored XSS, PrivEsc (Privilege Escalation), and Security Misconfiguration vulnerability, with a CVSS Score of 8.6, allows an unauthenticated attacker to

This Critical severity Stored XSS, PrivEsc (Privilege Escalation), and Security Misconfiguration vulnerability was introduced in versions 7.1.1, 7.4.0, 7.13.0, 7.17.0, 7.19.0, 8.0.0, 8.5.0, 8.9.0, 9.0.1, 9.1.0, 9.2.0, 9.3.1, 9.4.0, 9.5.1, 1

CWE-79: Cross-Site Scripting ✓ Offizieller Patch / Advisory verfügbar
💡 Gegenmaßnahme: Sicherheits-Update des Herstellers zeitnah einspielen und Netzwerksegmentierung prüfen.
18.08.2026
🛡️ Details ➔