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.
CVE-2026-35537
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.5%, top 62% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EG Risk
- 34(Track)EG Risk 34/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 38%
- KEV
- Not listed
Published
April 3, 2026
Last Modified
July 24, 2026
Advisory Details (8)
Auto-updated Jul 24, 2026oss-security - CVE-2026-35537+more: Roundcube arbitrary write + ID/XSS/etc. prior to 1.6.14
http://www.openwall.com/lists/oss-security/2026/04/11/6Security updates 1.7-rc5, 1.6.14 and 1.5.14 released
https://roundcube.net/news/2026/03/18/security-updates-1.7-rc5-1.6.14-1.5.14Roundcube Webmail 1.7 RC5
Patch available: roundcube/roundcubemail 1.7-rc5 (pre-release)
https://github.com/roundcube/roundcubemail/releases/tag/1.7-rc5Roundcube Webmail 1.6.14
Patch available: roundcube/roundcubemail 1.6.14
https://github.com/roundcube/roundcubemail/releases/tag/1.6.14Roundcube Webmail 1.5.14
Patch available: roundcube/roundcubemail 1.5.14
https://github.com/roundcube/roundcubemail/releases/tag/1.5.14commit a4ead994d2f0 (roundcube/roundcubemail)
Fix landed in roundcube/roundcubemail commit a4ead994d2f0 — awaiting tagged release
https://github.com/roundcube/roundcubemail/commit/a4ead994d2f0ea92e4a1603196a197e0d5df1620commit 6d586cfa4d8a (roundcube/roundcubemail)
Fix landed in roundcube/roundcubemail commit 6d586cfa4d8a — awaiting tagged release
https://github.com/roundcube/roundcubemail/commit/6d586cfa4d8a31f7957f7a445aaedd52592a0e74commit 618c5428edc6 (roundcube/roundcubemail)
Fix landed in roundcube/roundcubemail commit 618c5428edc6 — awaiting tagged release
https://github.com/roundcube/roundcubemail/commit/618c5428edc69fb088e7ac6c89e506dd39df3Affected Packages
(1 across 1 ecosystem)
Packagist(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| roundcube/roundcubemail | 1.7-beta ... 1.7-rc4 (6 versions) | 1.7-rc5 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 15× in last 7d / 45× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 108 total refreshes for this CVE.
- 2026-07-27 14:13 UTCEPSS rescore
- 2026-07-26 14:54 UTCEPSS rescore
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- 2026-07-26 09:21 UTCEG score recompute▲ 3.80
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- 2026-07-24 22:12 UTCNVD updateCVSS v3 → 7.5 · severity → HIGH
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Related CVEs(same CWE)
Same CWE
10 shownCWE-502
- CVE-2017-10992EG 9.8EPSS p95CRITICAL
- CVE-2013-4521EG 9.8EPSS p90CRITICAL
- CVE-2014-1860EG 9.8CRITICAL
- CVE-2016-1000027EG 9.8EPSS p98CRITICAL
- CVE-2014-3699EG 9.8CRITICAL
- CVE-2017-10934EG 9.8CRITICAL
- CVE-2016-9498EG 9.8EPSS p97CRITICAL
- CVE-2016-9483EG 9.8CRITICAL
- CVE-2015-2020EG 9.8CRITICAL
- CVE-2017-15692EG 9.8EPSS p91CRITICAL
Frequently asked(5)
What is CVE-2026-35537?
When was CVE-2026-35537 disclosed?
Is CVE-2026-35537 actively exploited?
What is the CVSS score of CVE-2026-35537?
How do I remediate CVE-2026-35537?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-35537
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