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Fencer Vulns
medium 5.3

CVE-2026-35542 json

Roundcube: Bypass of remote image blocking via crafted BODY background attribute

published 2026-04-03 7 mo ago modified 2026-07-24 3 mo ago also GHSA-5hf6-crg4-fg59 , EUVD-2026-18587

cvss
5.3
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 36%
public exploits
0
none known

Summary

An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. The remote image blocking feature can be bypassed via a crafted background attribute of a BODY element in an e-mail message. This may lead to information disclosure or access-control bypass.

Patch / fix

  • packagist roundcube/roundcubemail 1.7-rc5
  • Roundcube Webmail 1.5.14, 1.6.14
  • roundcube Debian 12 1.6.5+dfsg-1+deb12u8
  • roundcube Debian 13 1.6.15+dfsg-0+deb13u1
  • roundcube Debian 14 1.6.14+dfsg-1

debian advisories DEBIAN-CVE-2026-35542

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-2026-35542 updated cvss 4.3

roundcubemail: Roundcube Webmail: Information disclosure or access-control bypass via crafted email background attribute

  • 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
yes
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.42% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem package affected fixed in
packagist roundcube/roundcubemail
>=1.7-beta, <1.7-rc5
1.7-rc5

Affected products

  • Roundcube Webmail

Classification

Weakness
  • CWE-669 Incorrect Resource Transfer Between Spheres

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.