CVE-2026-35540

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 77% 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).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — 3 sources updated this week
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

An issue was discovered in Roundcube Webmail 1.6.0 before 1.6.14. Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links point to local network hosts.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: 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 computed
Severity65% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
23%
KEV
Not listed

Published

April 3, 2026

Last Modified

July 24, 2026

Advisory Details (5)

Auto-updated Jul 25, 2026
Patch available. Sources: github_commit, github_release.
generic

Security updates 1.7-rc5, 1.6.14 and 1.5.14 released

https://roundcube.net/news/2026/03/18/security-updates-1.7-rc5-1.6.14-1.5.14
github_release Patch Available

Roundcube Webmail 1.7 RC5

Patch available: roundcube/roundcubemail 1.7-rc5 (pre-release)

https://github.com/roundcube/roundcubemail/releases/tag/1.7-rc5
github_release Patch Available

Roundcube Webmail 1.6.14

Patch available: roundcube/roundcubemail 1.6.14

https://github.com/roundcube/roundcubemail/releases/tag/1.6.14
github_commit

commit 579b68eff906 (roundcube/roundcubemail)

Fix landed in roundcube/roundcubemail commit 579b68eff906 — awaiting tagged release

https://github.com/roundcube/roundcubemail/commit/579b68eff90650a5c782e153debd66c765648942
github_commit

commit 27ec6cc9cb25 (roundcube/roundcubemail)

Fix landed in roundcube/roundcubemail commit 27ec6cc9cb25 — awaiting tagged release

https://github.com/roundcube/roundcubemail/commit/27ec6cc9cb25e1ef8b4d4ef39ce76d619caa6870

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFixed inDependents
roundcube/roundcubemail1.7-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.

  1. 2026-07-27 14:13 UTCEPSS rescore
  2. 2026-07-26 14:54 UTCEPSS rescore
  3. 2026-07-26 14:54 UTCEPSS rescore
  4. 2026-07-26 09:21 UTCEG score recompute▲ 1.10
  5. 2026-07-25 14:18 UTCEPSS rescore
  6. 2026-07-25 14:18 UTCEPSS rescore
  7. 2026-07-24 22:12 UTCNVD updateCVSS v3 → 6.5
  8. 2026-07-24 14:17 UTCEPSS rescore
  9. 2026-07-24 14:17 UTCEPSS rescore
  10. 2026-07-23 14:18 UTCEPSS rescore
  11. 2026-07-23 14:18 UTCEPSS rescore
  12. 2026-07-23 03:10 UTCEG score recompute
  13. 2026-07-22 14:08 UTCEPSS rescore
  14. 2026-07-21 15:24 UTCEPSS rescore
  15. 2026-07-20 17:08 UTCEPSS rescore
  16. 2026-07-19 14:31 UTCEPSS rescore
  17. 2026-07-19 02:29 UTCEPSS rescore
  18. 2026-07-18 10:04 UTCEPSS rescore
  19. 2026-07-17 03:24 UTCOSV refresh
  20. 2026-07-16 17:03 UTCEPSS rescore
  21. 2026-07-15 16:57 UTCEPSS rescore
  22. 2026-07-15 16:57 UTCEPSS rescore
  23. 2026-07-15 02:00 UTCEPSS rescore
  24. 2026-07-13 22:30 UTCEPSS rescore
  25. 2026-07-13 06:13 UTCEPSS rescore
Show 75 more
  1. 2026-07-13 06:13 UTCEPSS rescore
  2. 2026-07-12 05:46 UTCEPSS rescore
  3. 2026-07-11 08:27 UTCEPSS rescore
  4. 2026-07-09 19:10 UTCEPSS rescore
  5. 2026-07-08 15:15 UTCEPSS rescore
  6. 2026-07-07 13:46 UTCEPSS rescore
  7. 2026-07-06 16:27 UTCEPSS rescore
  8. 2026-07-06 16:27 UTCEPSS rescore
  9. 2026-07-06 02:23 UTCEPSS rescore
  10. 2026-07-06 02:23 UTCEPSS rescore
  11. 2026-07-05 02:30 UTCEPSS rescore
  12. 2026-07-04 06:31 UTCEPSS rescore
  13. 2026-07-01 15:06 UTCEPSS rescore
  14. 2026-06-30 23:22 UTCEPSS rescore
  15. 2026-06-29 14:06 UTCEPSS rescore
  16. 2026-06-29 14:06 UTCEPSS rescore
  17. 2026-06-28 14:07 UTCEPSS rescore
  18. 2026-06-28 14:07 UTCEPSS rescore
  19. 2026-06-28 04:56 UTCEPSS rescore
  20. 2026-06-28 04:56 UTCEPSS rescore
  21. 2026-06-27 03:08 UTCEPSS rescore
  22. 2026-06-25 13:49 UTCEPSS rescore
  23. 2026-06-25 13:49 UTCEPSS rescore
  24. 2026-06-24 14:05 UTCEPSS rescore
  25. 2026-06-23 21:33 UTCEPSS rescore
  26. 2026-06-23 21:33 UTCEPSS rescore
  27. 2026-06-22 14:25 UTCEPSS rescore
  28. 2026-06-22 14:25 UTCEPSS rescore
  29. 2026-06-21 14:56 UTCEPSS rescore
  30. 2026-06-21 14:56 UTCEPSS rescore
  31. 2026-06-21 01:59 UTCEPSS rescore
  32. 2026-06-19 19:25 UTCEPSS rescore
  33. 2026-06-19 19:25 UTCEPSS rescore
  34. 2026-06-18 17:52 UTCEPSS rescore
  35. 2026-06-18 17:52 UTCEPSS rescore
  36. 2026-06-17 17:53 UTCEPSS rescore
  37. 2026-06-16 17:52 UTCEPSS rescore
  38. 2026-06-15 17:49 UTCEPSS rescore
  39. 2026-06-14 23:18 UTCEPSS rescore
  40. 2026-06-13 23:00 UTCEPSS rescore
  41. 2026-06-12 23:12 UTCEPSS rescore
  42. 2026-06-12 23:12 UTCEPSS rescore
  43. 2026-06-11 14:00 UTCEPSS rescore
  44. 2026-06-10 22:18 UTCEPSS rescore
  45. 2026-06-10 13:22 UTCEPSS rescore
  46. 2026-06-08 14:17 UTCEPSS rescore
  47. 2026-06-08 14:17 UTCEPSS rescore
  48. 2026-06-07 15:25 UTCEPSS rescore
  49. 2026-06-07 15:25 UTCEPSS rescore
  50. 2026-06-07 15:25 UTCEPSS rescore
  51. 2026-06-06 13:47 UTCEPSS rescore
  52. 2026-06-06 13:47 UTCEPSS rescore
  53. 2026-06-05 22:47 UTCEPSS rescore
  54. 2026-06-05 22:47 UTCEPSS rescore
  55. 2026-06-05 06:10 UTCEPSS rescore
  56. 2026-06-05 06:10 UTCEPSS rescore
  57. 2026-06-04 13:12 UTCEPSS rescore
  58. 2026-06-04 13:12 UTCEPSS rescore
  59. 2026-06-02 20:13 UTCEPSS rescore
  60. 2026-06-01 13:52 UTCEPSS rescore
  61. 2026-06-01 13:52 UTCEPSS rescore
  62. 2026-06-01 13:51 UTCEPSS rescore
  63. 2026-05-31 22:30 UTCEPSS rescore
  64. 2026-05-31 22:30 UTCEPSS rescore
  65. 2026-05-31 00:16 UTCEPSS rescore
  66. 2026-05-31 00:16 UTCEPSS rescore
  67. 2026-05-31 00:16 UTCEPSS rescore
  68. 2026-05-29 13:44 UTCEPSS rescore
  69. 2026-05-29 13:44 UTCEPSS rescore
  70. 2026-05-28 13:44 UTCEPSS rescore
  71. 2026-05-28 13:44 UTCEPSS rescore
  72. 2026-05-28 13:44 UTCEPSS rescore
  73. 2026-05-27 13:40 UTCEPSS rescore
  74. 2026-05-27 13:40 UTCEPSS rescore
  75. 2026-05-27 13:40 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-35540?
CVE-2026-35540 is a medium vulnerability published on April 3, 2026. An issue was discovered in Roundcube Webmail 1.6.0 before 1.6.14. Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links point to local network hosts.
When was CVE-2026-35540 disclosed?
CVE-2026-35540 was first published in the National Vulnerability Database on April 3, 2026, with the most recent update on July 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-35540 actively exploited?
CVE-2026-35540 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 76.7% of all scored CVEs.
What is the CVSS score of CVE-2026-35540?
CVE-2026-35540 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-35540?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-35540, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-35540

Explore →

Is Your Infrastructure Affected by CVE-2026-35540?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs