CVE-2020-26117

HIGHNVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2022-05-24. NVD baseline CVSS 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 3%CVSS: 8.1Exploit: None knownExposed: 0

A fix is available — apply it.

In rfb/CSecurityTLS.cxx and rfb/CSecurityTLS.java in TigerVNC before 1.11.0, viewers mishandle TLS certificate exceptions. They store the certificates as authorities, meaning that the owner of a certificate could impersonate any server after a client had added an exception.

CVSS v3
8.1
EG Score
8.1(medium)
EG Risk
42(Track)
EG Risk 42/100SSVC: 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
Severity81% × 45%
Exploitation3% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
3%
EPSS %ILE
87%
KEV
Not listed

Published

September 27, 2020

Last Modified

November 21, 2024

Advisory Details (7)

Auto-updated Sep 9, 2026
Patch available. Sources: github_release, github_commit.
generic Patch Available

[SECURITY] [DLA 2396-1] tigervnc security update

https://lists.debian.org/debian-lts-announce/2020/10/msg00007.html
github_release Patch Available

TigerVNC 1.11.0

Patch available: TigerVNC/tigervnc v1.11.0

https://github.com/TigerVNC/tigervnc/releases/tag/v1.11.0
github_commit Patch Available

commit f029745f63ac (TigerVNC/tigervnc)

Patch available: TigerVNC/tigervnc v1.11.90 (contains commit f029745f63ac)

https://github.com/TigerVNC/tigervnc/commit/f029745f63ac7d22fb91639b2cb5b3ab56134d6e
github_commit Patch Available

commit b30f10c681ec (TigerVNC/tigervnc)

Patch available: TigerVNC/tigervnc v1.11.90 (contains commit b30f10c681ec)

https://github.com/TigerVNC/tigervnc/commit/b30f10c681ec87720cff85d490f67098568a9cba
github_commit Patch Available

commit 7399eab79a43 (TigerVNC/tigervnc)

Patch available: TigerVNC/tigervnc v1.11.0 (contains commit 7399eab79a43)

https://github.com/TigerVNC/tigervnc/commit/7399eab79a4365434d26494fa1628ce1eb91562b
github_commit Patch Available

commit 20dea801e747 (TigerVNC/tigervnc)

Patch available: TigerVNC/tigervnc v1.11.0 (contains commit 20dea801e747)

https://github.com/TigerVNC/tigervnc/commit/20dea801e747318525a5859fe4f37c52b05310cb
generic

Making sure you're not a bot!

https://bugzilla.opensuse.org/show_bug.cgi?id=1176733

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntutigervnc-viewer (1.10.1+dfsg-3ubuntu0.1+esm2) @ focal2026-05-23ubuntu
redhattigervnc-0:1.11.0-6.el82021-05-18redhat

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

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
tigervnc—1.10.1+dfsg-9—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
tigervnc—1.10.1+dfsg-9—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
tigervnc—1.10.1+dfsg-9—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
tigervnc—1.10.1+dfsg-9—
Debian:9(1)
PackageVulnerable rangeFixed inDependents
tigervnc1.7.0+dfsg-7, 1.7.0+dfsg-7+deb9u11.7.0+dfsg-7+deb9u2—

Weakness Classification(1)

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

All Vendor Advisories

(2)

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 6× in last 7d / 24× 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 147 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2020-26117?
CVE-2020-26117 is a high vulnerability published on September 27, 2020. In rfb/CSecurityTLS.cxx and rfb/CSecurityTLS.java in TigerVNC before 1.11.0, viewers mishandle TLS certificate exceptions. They store the certificates as authorities, meaning that the owner of a certificate could impersonate any server after a client had added an exception.
When was CVE-2020-26117 disclosed?
CVE-2020-26117 was first published in the National Vulnerability Database on September 27, 2020, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-26117 actively exploited?
CVE-2020-26117 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3% probability of exploitation in the next 30 days, which ranks it in the top 13.0% of all scored CVEs.
What is the CVSS score of CVE-2020-26117?
CVE-2020-26117 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2020-26117?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-26117, 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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