CVE-2026-75000
CVE-2026-75000 — In Roundcube Webmail before 1.6.18 and 1.7.x before 1.7.3, improper HTML/CSS sanitization of the SVG animate "by" attribute may lead to…
In Roundcube Webmail before 1.6.18 and 1.7.x before 1.7.3, improper HTML/CSS sanitization of the SVG animate "by" attribute may lead to remote image blocking bypass, which in turn may lead to information disclosure or privilege escalation.
Published Updated Sources: NVD, roundcube (CNA), GitHub, SOCRadar CTI
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Exploit code
public exploit, none observed
EPSS
0%
ahead of 0% of scored CVEs
CVSS base
5.8
medium
Remediation
The vendor's own words where we have them.
Upgrade webmail to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.
First 24 hours
Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.
- Identify exposed assets running affected vendor/product/version combinations.
- Prioritize based on EPSS, PoC availability, and external exposure.
- Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.
Affected scope
Vendor, product and version as the advisories word them.
| Vendor | Product | Versions | Status |
|---|---|---|---|
| roundcube | webmail | — | Vulnerable |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Availability
None
Confidentiality
Low
Integrity
None
Scope
Changed
Attack Complexity
Low
Attack Vector
Network
Privileges Req
None
User Interaction
None
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 5.8 | CVSS 3.1 | medium | 3.9 | 1.4 | MITRE (CNA) |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N
What this weakness leads to
MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.
CWE-669 · Incorrect Resource Transfer Between Spheres
- Read Application Data
- Modify Application Data
- Unexpected State::
Weakness & attack patterns
- CWE-669
Inferred from the weakness class — not observed against this CVE.
Public exploit
Capability, not use: code existing is a different claim from anyone running it.
Repositories
4
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Search application, proxy, and WAF logs for requests touching /CSS.
- Prioritize edge telemetry for network-reachable webmail.
- Monitor for scanner or exploit-pattern traffic after 4 public PoC repositories were reported.
Timeline
What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.
- 2026
Added · CVSS 3.1 5.8 (AV:N)
Aug 17, 2026 · NVD
Initial · CVE published
Aug 17, 2026 · NVD
CVE published by mitre
Aug 17, 2026 · SOCRadar CTI
References
3 on the record
- github.com/roundcube/roundcubemail/releases/tag/1.6.18
Exploit, Third Party Advisory
- github.com/roundcube/roundcubemail/releases/tag/1.7.3
Exploit, Third Party Advisory
- roundcube.net/news/2026/08/09/security-updates-1.6.18-and-1.7.3
Vendor Advisory
Elsewhere on this site
- roundcubeevery CVE for this vendor
- Remote Code Execsame class
- CWE-669other pages naming this weakness
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record1
What should defenders know first?
CVE-2026-75000 is In Roundcube Webmail before 1.6.18 and 1.7.x before 1.7.3, improper HTML/CSS sanitization of the SVG animate "by" attribute may lead to…, a medium vulnerability affecting webmail from roundcube. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-75000. Public exploit evidence is: 4 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 5.8 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.