CVE-2026-35539
Roundcube Webmail: Insufficient HTML attachment sanitization in preview mode
An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.
- Record
CVE-2026-35539- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2026-18581
An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.
- Record
EUVD-2026-18581- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-x4q5-8j5g-hpjc
Roundcube Webmail: Insufficient HTML attachment sanitization in preview mode
An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.
- Record
GHSA-x4q5-8j5g-hpjc- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.
- Record
CVE-2026-35539- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.
- Record
CVE-2026-35539- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-35539
An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.
- Record
DEBIAN-CVE-2026-35539- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-x4q5-8j5g-hpjc
Roundcube Webmail: Insufficient HTML attachment sanitization in preview mode
An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.
- Record
GHSA-x4q5-8j5g-hpjc- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-35539
An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.
- Record
UBUNTU-CVE-2026-35539- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
roundcube/roundcubemailPackagist |
1.7-beta up to 1.7-rc5 | 1.7-rc5 |
roundcubeDebian:12 |
before 1.6.5+dfsg-1+deb12u8, plus listed versions 1.6.1+dfsg-11.6.2+dfsg-11.6.3+dfsg-11.6.3+dfsg-1~deb12u11.6.3+dfsg-2 Show 10 moreShow less1.6.4+dfsg-11.6.4+dfsg-1~deb12u11.6.5+dfsg-11.6.5+dfsg-1+deb12u21.6.5+dfsg-1+deb12u31.6.5+dfsg-1+deb12u41.6.5+dfsg-1+deb12u51.6.5+dfsg-1+deb12u61.6.5+dfsg-1+deb12u71.6.5+dfsg-1~deb12u1 |
1.6.5+dfsg-1+deb12u8 |
roundcubeDebian:13 |
before 1.6.15+dfsg-0+deb13u1, plus listed versions 1.6.11+dfsg-11.6.12+dfsg-0+deb13u11.6.12+dfsg-11.6.13+dfsg-0+deb13u11.6.13+dfsg-11.6.14+dfsg-1 |
1.6.15+dfsg-0+deb13u1 |
roundcubeDebian:14 |
before 1.6.14+dfsg-1, plus listed versions 1.6.11+dfsg-11.6.12+dfsg-11.6.13+dfsg-1 |
1.6.14+dfsg-1 |
roundcube/roundcubemailPackagist |
1.7-beta up to 1.7-rc5, plus listed versions 1.7-beta21.7-rc1.7-rc21.7-rc31.7-rc4 |
1.7-rc5 |
roundcubeUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 1.1.1+dfsg.1-21.1.2+dfsg.1-51.1.3+dfsg.1-11.1.4+dfsg.1-11.2~beta+dfsg.1-0ubuntu1 Show 8 moreShow less1.2~beta+dfsg.1-0ubuntu1+esm11.2~beta+dfsg.1-0ubuntu1+esm21.2~beta+dfsg.1-0ubuntu1+esm31.2~beta+dfsg.1-0ubuntu1+esm41.2~beta+dfsg.1-0ubuntu1+esm51.2~beta+dfsg.1-0ubuntu1+esm61.2~beta+dfsg.1-0ubuntu1+esm71.2~beta+dfsg.1-0ubuntu1+esm8 |
None known |
roundcubeUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 1.3.0+dfsg.1-11.3.1+dfsg.1-11.3.3+dfsg.1-11.3.3+dfsg.1-21.3.6+dfsg.1-1 Show 8 moreShow less1.3.6+dfsg.1-1ubuntu0.1~esm11.3.6+dfsg.1-1ubuntu0.1~esm21.3.6+dfsg.1-1ubuntu0.1~esm31.3.6+dfsg.1-1ubuntu0.1~esm41.3.6+dfsg.1-1ubuntu0.1~esm51.3.6+dfsg.1-1ubuntu0.1~esm61.3.6+dfsg.1-1ubuntu0.1~esm71.3.6+dfsg.1-1ubuntu0.1~esm8 |
None known |
roundcubeUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 1.3.8+dfsg.1-21.3.10+dfsg.1-11.4.1+dfsg.1-21.4.2+dfsg.1-11.4.2+dfsg.1-2 Show 9 moreShow less1.4.3+dfsg.1-11.4.3+dfsg.1-1ubuntu0.1~esm11.4.3+dfsg.1-1ubuntu0.1~esm21.4.3+dfsg.1-1ubuntu0.1~esm31.4.3+dfsg.1-1ubuntu0.1~esm41.4.3+dfsg.1-1ubuntu0.1~esm51.4.3+dfsg.1-1ubuntu0.1~esm61.4.3+dfsg.1-1ubuntu0.1~esm71.4.3+dfsg.1-1ubuntu0.1~esm8 |
None known |
roundcubeUbuntu:Pro:22.04:LTS |
All versions, plus listed versions 1.4.11+dfsg.1-41.5.0+dfsg.1-21.5.0+dfsg.1-2ubuntu0.1~esm11.5.0+dfsg.1-2ubuntu0.1~esm21.5.0+dfsg.1-2ubuntu0.1~esm31.5.0+dfsg.1-2ubuntu0.1~esm41.5.0+dfsg.1-2ubuntu0.1~esm51.5.0+dfsg.1-2ubuntu0.1~esm6 |
None known |
roundcubeUbuntu:Pro:24.04:LTS |
All versions, plus listed versions 1.6.2+dfsg-11.6.4+dfsg-11.6.5+dfsg-11.6.6+dfsg-11.6.6+dfsg-2 Show 4 moreShow less1.6.6+dfsg-2ubuntu0.11.6.6+dfsg-2ubuntu0.1+esm11.6.6+dfsg-2ubuntu0.1+esm21.6.6+dfsg-2ubuntu0.1+esm3 |
None known |
roundcubeUbuntu:25.10 |
All versions, plus listed versions 1.6.10+dfsg-11.6.10+dfsg-21.6.11+dfsg-1 |
None known |
roundcubeUbuntu:26.10 |
All versions, plus listed versions 1.6.11+dfsg-1 |
None known |
roundcubeUbuntu:Pro:26.04:LTS |
All versions, plus listed versions 1.6.11+dfsg-11.6.11+dfsg-1ubuntu0.26.04.1~esm1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-35539 is a medium vulnerability (CVSS 6.1) in Bulwarkmail Webmail, published April 3, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.26%, the 17th percentile. Fixed in roundcube/roundcubemail 1.7-rc5.
References
roundcube.net/news/2026/03/18/security-updates-1.7-rc5-1.6.14-1.5.14
github.com/roundcube/roundcubemail/releases/tag/1.7-rc5
Show 8 moreShow less
nvd.nist.gov/vuln/detail/CVE-2026-35539
security-tracker.debian.org/tracker/CVE-2026-35539
ubuntu.com/security/CVE-2026-35539
cve.org/CVERecord?id=CVE-2026-35539