Read the docs
TI-2026-79181 Aliases CVE-2026-114731GHSA-mpw2-q5qr-3w4j

Uncontrolled resource consumption in Roundcube Webmail CSS proxy

Priority LOW 30CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · Low
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-770.

Summary

Roundcube Webmail from 1.6.0 before 1.6.20 and from 1.7.0 before 1.7.5 is affected. The CSS proxy in the utils/modcss action read fetched stylesheets fully into memory with no size limit or read timeout (CWE-770). A remote attacker who needs no privileges or user interaction can point a stylesheet URL at a host they control to exhaust server memory.

Written with Claude Haiku 5.5 from the sources below · 2026-11-02

Description from the CNA

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by an uncontrolled resource consumption vulnerability in the CSS proxy (the utils/modcss action). The fetched stylesheet was read into memory in full, with no size limit and no read timeout, so a stylesheet URL referencing an attacker-controlled host could be used to exhaust server memory. Upstream fixed this in the commit “Add a size limit to the CSS proxy content processing”, which caps the response at 5 MB, reads it as a stream and applies a read timeout.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00432 37th percentileScored 2026-11-07
Fix Fixed Webmail (Roundcube): 1.6.20, 1.7.5

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
RoundcubeWebmail1.6.0 to before 1.6.20; 1.7.0 to before 1.7.51.6.20, 1.7.5Patch availableCNA
  • Webmail VendorRoundcube Affected 1.6.0 to before 1.6.20; 1.7.0 to before 1.7.5 Fixed in 1.6.20, 1.7.5 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*1.6.0 to before 1.6.20; 1.7.0 to before 1.7.5VulnerableRoundcube
  • cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:* Versions 1.6.0 to before 1.6.20; 1.7.0 to before 1.7.5 Vulnerable ·Roundcube

Remediation

Upgrade Roundcube Webmail to 1.6.20 or 1.7.5. The fix caps the proxied response at 5 MB, reads it as a stream and applies a read timeout.

Written with Claude Haiku 5.5 from the sources below · 2026-11-02

  • Fix · CNA Webmail (Roundcube) Fixed in 1.6.20, 1.7.5

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    Roundcube Webmail — roundcube.net/news/2026/10/19/security-updates-1.6.20-and-1…

    20 records Highest priority Priority LOW 20 LOW

    Other records, highest priority first

    • TI-2026-79180 Server-side request forgery filter bypass in Roundcube WebmailPriority LOW 38
    • TI-2026-79177 Roundcube Webmail passes unsafe SVG and EPS content to ImageMagickPriority LOW 38
    • TI-2026-79182 Improper authentication in Roundcube Webmail multi-host alias loginsPriority LOW 37
    Show all 20 records → Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-22 Threatist record created from CVE-2026-114731
  2. 2026-10-22 Alias added: GHSA-mpw2-q5qr-3w4j
  3. 2026-10-29 Affected versions changed · Red Hat
  4. 2026-10-29 CVSS score added · Red Hat
  5. 2026-11-02 CISA SSVC decision points changed

References

Patch 4

Advisory 2

  • TI-2025-31204 Deserialization of untrusted data in Roundcube Webmail KEVCVSS 3.1CRITICAL 9.9
  • TI-2021-19778 Roundcube before 1.3.17 and 1.4.x before 1.4.12 is prone to a potential SQL injection via search or search_params. KEVCVSS 3.1CRITICAL 9.8
  • TI-2020-10051 rcube_image.php in Roundcube Webmail before 1.4.4 allows attackers to execute arbitrary… KEVCVSS 3.1CRITICAL 9.8
  • TI-2024-28025 A Cross-Site Scripting vulnerability in Roundcube through 1.5.7 and 1.6.x through 1.6.7… KEVCVSS 3.1CRITICAL 9.3
  • TI-2017-12250 Roundcube Webmail before 1.1.10, 1.2.x before 1.2.7, and 1.3.x before 1.3.3 allows… KEVCVSS 3.1HIGH 7.8
  • TI-2025-41994 Cross-site scripting in Roundcube Webmail KEVCVSS 3.1HIGH 7.2
See all 112 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences