CVE-2016-9942

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2022-05-13. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 4%CVSS: 9.8Exploit: NoneExposed: 0

A fix is available — apply it.

Heap-based buffer overflow in ultra.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted FramebufferUpdate message with the Ultra type tile, such that the LZO payload decompressed length exceeds what is specified by the tile dimensions.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
50(Track)
EG Risk 50/100SSVC: 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
Severity98% × 45%
Exploitation4% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
88.7%
KEV
Not listed

Published

December 31, 2016

Last Modified

May 6, 2026

Advisory Details (6)

Auto-updated May 9, 2026
Patch available.
generic

Fix two heap buffer overflows by atx · Pull Request #137 · LibVNC/libvncserver · GitHub

https://github.com/LibVNC/libvncserver/pull/137
generic
http://www.securityfocus.com/bid/95170
generic Patch Available

[SECURITY] [DSA 3753-1] libvncserver security update

http://www.debian.org/security/2017/dsa-3753
generic

LibVNCServer/LibVNCClient: Multiple vulnerabilities (GLSA 201702-24) — Gentoo security

https://security.gentoo.org/glsa/201702-24
generic Patch Available

[SECURITY] [DLA 1979-1] italc security update

https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html
generic

Release LibVNCServer-0.9.11 · LibVNC/libvncserver · GitHub

https://github.com/LibVNC/libvncserver/releases/tag/LibVNCServer-0.9.11

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibitalccore (1:2.0.2+dfsg1-4ubuntu0.1) @ xenial2026-05-20ubuntu
ubuntulibvncserver0 (0.9.8.2-2ubuntu1.2) @ precise2026-05-20ubuntu

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.

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 12× in last 7d / 41× 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 117 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2016-9942?
CVE-2016-9942 is a critical vulnerability published on December 31, 2016. Heap-based buffer overflow in ultra.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted FramebufferUpdate message with the Ultra type tile, such that the LZO payload decompressed…
When was CVE-2016-9942 disclosed?
CVE-2016-9942 was first published in the National Vulnerability Database on December 31, 2016, with the most recent update on May 6, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2016-9942 actively exploited?
CVE-2016-9942 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 88.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2016-9942?
CVE-2016-9942 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2016-9942?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2016-9942, 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.

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