Stored XSS in Roundcube Webmail SVG email handling
CVE-2023-5631 is a stored cross-site scripting vulnerability in Roundcube Webmail caused by improper sanitization of malicious SVG content in HTML email messages. The issue is attributed to behavior in program/lib/Roundcube/rcube_washtml.php. A remote attacker can send a specially crafted HTML email containing an SVG document with attacker-controlled script payloads, including JavaScript embedded via constructs such as an onerror handler. When the victim views the message in Roundcube, the payload executes in the context of the victim’s authenticated Roundcube web session. The vulnerability affects Roundcube before 1.4.15, 1.5.x before 1.5.5, and 1.6.x before 1.6.4. Reporting indicates exploitation required no interaction beyond opening the malicious email in a browser-based Roundcube session.
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Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
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Remediation
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
6 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A stored XSS vulnerability in Roundcube Webmail that was exploited as a zero-day by Russian-linked threat actors against European and Ukrainian government targets.
A Roundcube vulnerability added to CISA KEV due to exploitation in multiple campaigns, including Winter Vivern targeting European government and military entities.
A zero-day XSS vulnerability in Roundcube Webmail exploited by the threat actor Winter Vivern to compromise government entities and think tanks in Europe.
A Cross-Site Scripting (XSS) vulnerability in Roundcube webmail that TAG-70 exploited to access, list, and exfiltrate mailbox contents after the victim opens a malicious email.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.