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Fencer Vulns
medium 4.7

CVE-2026-26079 json

Roundcube Webmail before 1.5.13 and 1.6 before 1.6.13 allows Cascading Style Sheets (CSS) injection, e.g., because comments are mishandled.

published 2026-02-11 8 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-5945

cvss
4.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 29%
public exploits
0
none known

Summary

Roundcube Webmail before 1.5.13 and 1.6 before 1.6.13 allows Cascading Style Sheets (CSS) injection, e.g., because comments are mishandled.

Patch / fix

  • Roundcube Webmail 1.5.13, 1.6.13
  • roundcube Debian 12 1.6.5+dfsg-1+deb12u7
  • roundcube Debian 13 1.6.13+dfsg-0+deb13u1
  • roundcube Debian 14 1.6.13+dfsg-1

debian advisories DEBIAN-CVE-2026-26079

  • roundcube Ubuntu Pro 16.04 LTS 1.2~beta+dfsg.1-0ubuntu1+esm8
  • roundcube Ubuntu Pro 18.04 LTS 1.3.6+dfsg.1-1ubuntu0.1~esm8
  • roundcube Ubuntu Pro 20.04 LTS 1.4.3+dfsg.1-1ubuntu0.1~esm8
  • roundcube Ubuntu Pro 22.04 LTS 1.5.0+dfsg.1-2ubuntu0.1~esm6
  • roundcube Ubuntu Pro 24.04 LTS 1.6.6+dfsg-2ubuntu0.1+esm3

ubuntu advisories UBUNTU-CVE-2026-26079

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • roundcubemail openSUSE Leap 16.0 1.6.13-bp160.1.1

opensuse advisories openSUSE-SU-2026:20323-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-26079 updated cvss 4.7

roundcubemail: Roundcube Webmail: Cascading Style Sheets (CSS) injection via mishandled comments

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
8 mo ago

Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 29% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.7 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N

Affected products

  • Roundcube Webmail

Classification

Weakness
  • CWE-829 Inclusion of Functionality from Untrusted Control Sphere

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.