CVE-2026-35545 is a medium-severity (CVSS 5.3) CWE-669 vulnerability in roundcube/roundcubemail. A fix is available for roundcube/roundcubemail — see the affected versions and patch details below.
Roundcube Webmail: Remote image blocking feature can be bypassed via SVG content in an e-mail message
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-35545.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
roundcube/roundcubemailReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
An issue was discovered in Roundcube Webmail before 1.5.15 and 1.6.15. The remote image blocking feature can be bypassed via SVG content in an e-mail message. This may lead to information disclosure or access-control bypass. This involves the animate element with attributeName=fill/filter/stroke.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | roundcube/roundcubemail | ≥ 1.7-beta&&< 1.7-rc5 | 1.7-rc5composer require roundcube/roundcubemail:^1.7-rc5 |
Affected Products
webmailroundcubeDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for roundcube/roundcubemail, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update roundcube/roundcubemail to 1.7-rc5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-35545 is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.
Frequently Asked Questions
Is CVE-2026-35545 in your dependencies?
Find it across Packagist, including transitive dependencies.