CVE-2020-35730

CRITICALNVD 6.19.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2023-06-22), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 6.1 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 5 sources updated this weekExploited in the wild
9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 33%CVSS: 6.1Exploit: cisa kev · ssvc active · epss top5pctExposed: 0

A fix is available — apply it.

An XSS issue was discovered in Roundcube Webmail before 1.2.13, 1.3.x before 1.3.16, and 1.4.x before 1.4.10. The attacker can send a plain text e-mail message, with JavaScript in a link reference element that is mishandled by linkref_addindex in rcube_string_replacer.php.

CVSS v3
6.1
EG Score
9.0(high)
EG Risk
81(Attend)
EG Risk 81/100SSVC: Attend

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
Severity90% × 45%
Exploitation100% × 40%
Automatability0% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
33%
EPSS %ILE
98%
KEV
⚠ Exploited

Published

December 28, 2020

Last Modified

November 4, 2025

Advisory Details (8)

Auto-updated Jun 13, 2026
Patch available. Sources: github_release.
generic Patch Available

#978491 - roundcube: CVE-2020-35730: XSS vulnerability via malious HTML or plaintext messages - Debian Bug report logs

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=978491
generic

Roundcube Webmail Downloads

https://roundcube.net/download/
generic

[SECURITY] Fedora 32 Update: roundcubemail-1.4.10-1.fc32 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HMLIZWKMTRCLU7KZLEQHELS4INXJ7X5Q/
generic

[SECURITY] Fedora 33 Update: roundcubemail-1.4.10-1.fc33 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HCEU4BM5WGIDJWP6Z4PCH62ZMH57QYM2/
github_release Patch Available

Roundcube Webmail 1.4.10

Patch available: roundcube/roundcubemail 1.4.10

https://github.com/roundcube/roundcubemail/releases/tag/1.4.10
github_release Patch Available

Roundcube Webmail 1.3.16

Patch available: roundcube/roundcubemail 1.3.16

https://github.com/roundcube/roundcubemail/releases/tag/1.3.16
github_release Patch Available

Roundcube Webmail 1.2.13

Patch available: roundcube/roundcubemail 1.2.13

https://github.com/roundcube/roundcubemail/releases/tag/1.2.13
generic

Comparing 1.4.9...1.4.10 · roundcube/roundcubemail · GitHub

https://github.com/roundcube/roundcubemail/compare/1.4.9...1.4.10

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubunturoundcube-sqlite3 (1.2~beta+dfsg.1-0ubuntu1+esm2) @ xenial2026-08-21ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(6 across 6 ecosystems)
Debian:10(1)
PackageVulnerable rangeFixed inDependents
roundcube1.3.10+dfsg.1-1 ... 1.3.8+dfsg.1-2 (7 versions)1.3.16+dfsg.1-1~deb10u1—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
roundcube—1.4.10+dfsg.1-1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
roundcube—1.4.10+dfsg.1-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
roundcube—1.4.10+dfsg.1-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
roundcube—1.4.10+dfsg.1-1—
Debian:9(1)
PackageVulnerable rangeFixed inDependents
roundcube1.2.3+dfsg.1-4 ... 1.2.3+dfsg.1-4+deb9u7 (8 versions)1.2.3+dfsg.1-4+deb9u8—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 91× in last 7d / 330× 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 948 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(6)

What is CVE-2020-35730?
CVE-2020-35730 is a critical vulnerability published on December 28, 2020. An XSS issue was discovered in Roundcube Webmail before 1.2.13, 1.3.x before 1.3.16, and 1.4.x before 1.4.10. The attacker can send a plain text e-mail message, with JavaScript in a link reference element that is mishandled by linkrefaddindex in rcubestring_replacer.php.
When was CVE-2020-35730 disclosed?
CVE-2020-35730 was first published in the National Vulnerability Database on December 28, 2020, with the most recent update on November 4, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-35730 actively exploited?
Yes. CISA added CVE-2020-35730 to the Known Exploited Vulnerabilities catalog on June 22, 2023, affecting Roundcube Roundcube Webmail. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2020-35730?
CVE-2020-35730 has a CVSS v3 base score of 6.1 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2020-35730?
CVE-2020-35730 affects Roundcube Roundcube Webmail. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2020-35730?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-35730, 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

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