CVE-2026-11623

MEDIUMPre-NVD 4.54.5—
EchelonGraph scoreMEDIUM confidence

Score 4.5 from GitHub Security Advisory (severity: LOW) published 2026-06-09. a secondary CVSS source baseline 4.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
4.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.5Exploit: None knownExposed: 0

A fix is available — apply it.

A security vulnerability has been detected in tmux up to 3.6a. Affected is the function image_free of the file image.c. Such manipulation leads to use after free. Local access is required to approach this attack. This attack is characterized by high complexity. The exploitability is told to be difficult. The exploit has been disclosed publicly and may be used. Upgrading to version 3.7-rc is able to address this issue. The name of the patch is fc6d94a9f8a593bd8b7031650802084385d4ee03. The affected component should be upgraded.

CVSS v3
4.5
EG Score
4.5(medium)
EG Risk
20(Track)
EG Risk 20/100SSVC: 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
Severity45% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
2%
KEV
Not listed

Published

June 9, 2026

Last Modified

July 23, 2026

Advisory Details (4)

Auto-updated Jun 15, 2026
Patch available. Sources: github_release, github_commit.
github_release Patch Available

tmux 3.7-rc

Patch available: tmux/tmux 3.7-rc (pre-release)

https://github.com/tmux/tmux/releases/tag/3.7-rc
github_commit Patch Available

commit fc6d94a9f8a5 (tmux/tmux)

Patch available: tmux/tmux 3.7-rc (contains commit fc6d94a9f8a5)

https://github.com/tmux/tmux/commit/fc6d94a9f8a593bd8b7031650802084385d4ee03
generic

GitHub - tmux/tmux: tmux source code · GitHub

https://github.com/tmux/tmux/
generic

UAF Write Vulnerability During Sixel Image LRU Eviction · GitHub

https://gist.github.com/XlabAITeam/f0d9952595f795129a3258ba73bbc3cb

Vendor Advisories for CVE-2026-11623(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntutmux (3.6a-2ubuntu0.1) @ resolute2026-09-14ubuntu

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

(1 across 1 ecosystem)
Debian:14(1)
PackageVulnerable rangeFixed inDependents
tmux3.5a-3, 3.6a-1, 3.6a-2, 3.6b-1~bpo13+13.6b-1—

Weakness Classification(2)

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

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 9× in last 7d / 40× 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 224 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-11623?
CVE-2026-11623 is a medium vulnerability published on June 9, 2026. A security vulnerability has been detected in tmux up to 3.6a. Affected is the function image_free of the file image.c. Such manipulation leads to use after free. Local access is required to approach this attack. This attack is characterized by high complexity. The exploitability is told to be…
When was CVE-2026-11623 disclosed?
CVE-2026-11623 was first published in the National Vulnerability Database on June 9, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-11623 actively exploited?
CVE-2026-11623 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 97.5% of all scored CVEs.
What is the CVSS score of CVE-2026-11623?
CVE-2026-11623 has a CVSS v3 base score of 4.5 (NVD).
How do I remediate CVE-2026-11623?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-11623, 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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