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PatchSiren cyber security CVE debrief

CVE-2026-35545 Roundcube CVE debrief

CVE-2026-35545 is a vulnerability in Roundcube Webmail that allows remote image blocking to be bypassed via SVG content in an e-mail message. This may lead to information disclosure or access-control bypass. The vulnerability has a CVSS score of 5.3 and a severity of MEDIUM. Affected users should apply patches to prevent potential information disclosure or access-control bypass.

Vendor
Roundcube
Product
Webmail
CVSS
MEDIUM 5.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-04-03
Original CVE updated
2026-07-24
Advisory published
2026-04-03
Advisory updated
2026-07-24

Who should care

Users of Roundcube Webmail versions before 1.5.15 and 1.6.15 should apply patches to prevent potential information disclosure or access-control bypass. This vulnerability may impact operators, platforms, vulnerability-management teams, and security teams.

Technical summary

The remote image blocking feature in Roundcube Webmail can be bypassed via SVG content in an e-mail message. This involves the animate element with attributeName=fill/filter/stroke. The vulnerability has a CVSS score of 5.3 and a severity of MEDIUM. This issue was discovered in Roundcube Webmail before 1.5.15 and 1.6.15. Affected users should apply patches to prevent potential information disclosure or access-control bypass. The vulnerability may impact operators, platforms, vulnerability-management teams, and security teams. Users of Roundcube Webmail versions before 1.5.15 and 1.6.15 should apply patches to prevent potential information disclosure or access-control bypass.

Defensive priority

Apply patches to prevent potential information disclosure or access-control bypass.

Recommended defensive actions

  • Apply patches to Roundcube Webmail versions before 1.5.15 and 1.6.15
  • Restrict access to sensitive areas of the webmail interface
  • Monitor for suspicious activity
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record was published on 2026-04-03T05:16:22.980Z and was last modified on 2026-07-24T21:10:00.143Z. The NVD entry is currently Analyzed. This vulnerability affects Roundcube Webmail versions before 1.5.15 and 1.6.15. The remote image blocking feature can be bypassed via SVG content in an e-mail message, potentially leading to information disclosure or access-control bypass.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-35545 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-35545

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-35545 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-35545

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.