Cyber Posture

CVE-2026-48843

High
Microsoft: not affectedMSmacOS: not affectedMacLinux: not affectedLnxMobile: not affectedMobNetwork: not affectedNetApplication: not affectedAppOther: affectedOth

Published: 25 May 2026

Published
25 May 2026
Modified
26 May 2026
KEV Added
—
Patch
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CVSS Score 7.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
EPSS Score 0.0003 9.0th percentile
Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-48843 is a high-severity SSRF (CWE-918) vulnerability in Roundcube Webmail (inferred from references). Its CVSS base score is 7.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 9.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190).
Threat & Defense Details

Likely Mitigating ControlsAI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

CA-8 Penetration Testing
addresses: CWE-918

Penetration testing attempts server-side requests to internal resources, identifying SSRF weaknesses for remediation.

SC-7 Boundary Protection
addresses: CWE-918

Outbound connections to external resources can be monitored and limited at the boundary, reducing SSRF impact.

SI-10 Information Input Validation
addresses: CWE-918

Validates server-side URLs and resource references to block SSRF attempts.

SI-4 System Monitoring
addresses: CWE-918

Detects server-side request forgery through monitoring of unexpected outbound connections.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Why these techniques?

SSRF vulnerability in public-facing Roundcube webmail directly enables exploitation of the application via malicious email content.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

Roundcube Webmail 1.6.x between 1.6.14 and 1.6.16,and 1.7.x before 1.7.1 has Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links point to local network hosts. The issue stems…

more

from an insufficient fix for CVE-2026-35540.

Deeper analysisAI

Automated synthesis unavailable for this CVE.

Details

CWE(s)
CWE-918
OWASP Top 10 Web 2025
A01:2025

Affected Products

Roundcube
Webmail
inferred from references and description; NVD did not file a CPE for this CVE

EU & UK References

References