CVE-2026-25916Public exploitNetwork attack vector

Email-view tracking via unsanitized SVG feImage

Published Feb 9, 2026 · Updated Feb 9, 2026

Remote image-blocking bypass in Roundcube Webmail before 1.5.13 and 1.6 before 1.6.13 allows remote attackers to track email views. The rcube_washtml sanitizer misclassifies SVG feImage href attributes as ordinary links, so HTTP and HTTPS image URLs bypass the remote-resource filter. A crafted HTML email triggers an attacker-controlled request when a user views it, disclosing the view, IP address, and browser details without altering messages or service state.

CVSS severity4.3
Medium
EPSS probability0.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Remote image-blocking bypass in Roundcube Webmail before 1.5.13 and 1.6 before 1.6.13 allows remote attackers to track email views. The rcube_washtml sanitizer misclassifies SVG feImage href attributes as ordinary links, so HTTP and HTTPS image URLs bypass the remote-resource filter. A crafted HTML email triggers an attacker-controlled request when a user views it, disclosing the view, IP address, and browser details without altering messages or service state.

The record

CVE
CVE-2026-25916
Published
Feb 9, 2026
Updated
Feb 9, 2026
Vendor
Roundcube
Product
Roundcube Webmail
Classifications
CWE-420
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.5.13
  2. Affected versionversion=1.6.0 <1.6.13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Roundcube · Roundcube Webmailversion=0 <1.5.13; version=1.6.0 <1.6.13

Published CVSS scores

4.3MITRECVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-420Unprotected Alternate Channel

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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