Deserialization in Roundcube Webmail
CVE-2026-35537
An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. Unsafe deserialization in the redis/memcache session handler may lead to arbitrary file write operations by unauthenticated attackers via crafted session data.
Vulnerability class: Insecure Deserialization
EPSS: 0.000 (15.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N.
Affected products
- Roundcube Webmail — versions 0, 1.6.0
Weakness classification (CWE)
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
- github.com/roundcube/roundcubemail/commit/6d586cfa4d8a31f7957f7a445aaedd52592a0…
- github.com/roundcube/roundcubemail/releases/tag/1.6.14
- github.com/roundcube/roundcubemail/commit/a4ead994d2f0ea92e4a1603196a197e0d5df1…
- github.com/roundcube/roundcubemail/releases/tag/1.5.14
- github.com/roundcube/roundcubemail/commit/618c5428edc69fb088e7ac6c89e506dd39df3
Frequently asked questions
- What is CVE-2026-35537?
- CVE-2026-35537 is a low-severity vulnerability in Roundcube Webmail, classified under Deserialization of Untrusted Data. CVSS score: 3.7/10. Published 2026-04-03.
- How severe is CVE-2026-35537?
- Low severity. CVSS v3 base score is 3.7 out of 10.