CVE-2026-35543

An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. The remote image blocking feature can be bypassed via SVG content (with animate attributes) in an e-mail message. This may lead to information disclosure or access-control bypass.

Published: 2026-04-03 Last update: 2026-04-07 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-35543 is rated Low Risk (24.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.03%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-35543

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-03 0.03%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-35543

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 1.4 [email protected]

Weakness enumeration for CVE-2026-35543

GitHub Security Advisory for CVE-2026-35543

GHSA-j2g6-8rvg-7mf6 · Severity: medium · Ecosystem: composer — Roundcube Webmail: Bypass of remote image blocking via SVG content (with animate attributes) in an e-mail message

OS Trackers for CVE-2026-35543

vendor priority summary link
debian not yet assigned CVE-2026-35543 not yet assigned priority: Debian including 1 source packages (roundcube), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-35543
ubuntu medium CVE-2026-35543 medium priority: Ubuntu including 1 source packages (roundcube), 7 status rows across 7 suites (bionic, focal, jammy, noble, questing, upstream, xenial): needs-triage 6, released 1. https://ubuntu.com/security/CVE-2026-35543

Affected software / configurations for CVE-2026-35543

Vendor Product Version Raw CPE
roundcube webmail < 1.5.14 cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*
roundcube webmail >= 1.6.0, < 1.6.14 cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*

References for CVE-2026-35543

cvelogic Threat Intelligence