CVE-2026-55655

MEDIUMNVD 6.16.1—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.1 under NVD CVSS v3. EPSS exploit probability: 0.1%, top 100% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.1Exploit: None knownExposed: 0

A fix is available — apply it.

A flaw was found in OpenSSH. A local unprivileged attacker on a Linux client host can hijack client-side X11 forwarding connections. This is possible by pre-binding the preferred abstract X socket name when X11 forwarding is enabled and a local UNIX-domain X socket is used. A successful attack can compromise the confidentiality of forwarded X11 traffic, including sensitive window contents and input, and may allow some manipulation of the forwarded session.

CVSS v3
6.1
EG Score
6.1(medium)
EG Risk
27(Track)
EG Risk 27/100SSVC: 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
Severity61% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
0%
KEV
Not listed

Published

June 23, 2026

Last Modified

July 8, 2026

Advisory Details (2)

Auto-updated Jun 23, 2026
Patch available. Sources: redhat.
redhat

2462250 – (CVE-2026-55655) CVE-2026-55655 openssh: Local MITM of X11 forwarding via abstract UNIX socket pre-binding in Red Hat Enterprise Linux OpenSSH client versions

https://bugzilla.redhat.com/show_bug.cgi?id=2462250
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-55655

Vendor Advisories for CVE-2026-55655(3)

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
redhatopenssh-main-10.3p1-6.hum12026-07-08redhat

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.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 63× 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.

  1. 2026-07-26 15:55 UTCEG score recompute
  2. 2026-07-26 15:55 UTCVendor advisory
  3. 2026-07-26 15:55 UTCGHSA enrichment
  4. 2026-07-26 14:54 UTCEPSS rescore
  5. 2026-07-25 14:18 UTCEPSS rescore
  6. 2026-07-24 14:18 UTCEPSS rescore
  7. 2026-07-23 14:18 UTCEPSS rescore
  8. 2026-07-23 03:20 UTCEG score recompute▲ 1.10
  9. 2026-07-22 14:08 UTCEPSS rescore
  10. 2026-07-21 15:25 UTCEPSS rescore
  11. 2026-07-20 17:08 UTCEPSS rescore
  12. 2026-07-18 10:04 UTCEPSS rescore
  13. 2026-07-16 17:03 UTCEPSS rescore
  14. 2026-07-16 13:35 UTCVendor advisory
  15. 2026-07-16 13:35 UTCGHSA enrichment
  16. 2026-07-15 16:57 UTCEPSS rescore
  17. 2026-07-15 16:57 UTCEPSS rescore
  18. 2026-07-15 14:07 UTCVendor advisory
  19. 2026-07-15 14:07 UTCGHSA enrichment
  20. 2026-07-14 14:26 UTCVendor advisory
  21. 2026-07-14 14:26 UTCGHSA enrichment
  22. 2026-07-13 22:31 UTCEPSS rescore
  23. 2026-07-13 15:04 UTCVendor advisory
  24. 2026-07-13 15:04 UTCGHSA enrichment
  25. 2026-07-12 15:36 UTCVendor advisory
Show 49 more
  1. 2026-07-12 15:36 UTCGHSA enrichment
  2. 2026-07-12 05:46 UTCEPSS rescore
  3. 2026-07-11 16:07 UTCVendor advisory
  4. 2026-07-11 16:07 UTCGHSA enrichment
  5. 2026-07-10 16:45 UTCVendor advisory
  6. 2026-07-10 16:45 UTCGHSA enrichment
  7. 2026-07-09 19:10 UTCEPSS rescore
  8. 2026-07-09 19:10 UTCEPSS rescore
  9. 2026-07-09 17:23 UTCVendor advisory
  10. 2026-07-09 17:23 UTCGHSA enrichment
  11. 2026-07-08 17:58 UTCGHSA enrichment
  12. 2026-07-08 15:16 UTCEPSS rescore
  13. 2026-07-08 15:16 UTCEPSS rescore
  14. 2026-07-08 14:36 UTCNVD updateCVSS v3 → 6.1
  15. 2026-07-07 18:35 UTCGHSA enrichment
  16. 2026-07-07 13:46 UTCEPSS rescore
  17. 2026-07-07 13:46 UTCEPSS rescore
  18. 2026-07-06 19:11 UTCGHSA enrichment
  19. 2026-07-06 16:27 UTCEPSS rescore
  20. 2026-07-06 16:27 UTCEPSS rescore
  21. 2026-07-05 19:49 UTCGHSA enrichment
  22. 2026-07-04 20:27 UTCGHSA enrichment
  23. 2026-07-04 06:31 UTCEPSS rescore
  24. 2026-07-04 06:31 UTCEPSS rescore
  25. 2026-07-03 22:01 UTCMITRE cvelistV5CVSS v3 → 5
  26. 2026-07-03 21:05 UTCGHSA enrichment
  27. 2026-07-02 21:43 UTCGHSA enrichment
  28. 2026-07-01 22:21 UTCGHSA enrichment
  29. 2026-07-01 15:07 UTCEPSS rescore
  30. 2026-06-30 22:45 UTCGHSA enrichment
  31. 2026-06-29 23:23 UTCGHSA enrichment
  32. 2026-06-29 14:06 UTCEPSS rescore
  33. 2026-06-29 14:06 UTCEPSS rescore
  34. 2026-06-29 00:02 UTCGHSA enrichment
  35. 2026-06-28 14:07 UTCEPSS rescore
  36. 2026-06-28 04:56 UTCEPSS rescore
  37. 2026-06-28 04:56 UTCEPSS rescore
  38. 2026-06-28 00:39 UTCGHSA enrichment
  39. 2026-06-27 03:08 UTCEPSS rescore
  40. 2026-06-27 01:16 UTCGHSA enrichment
  41. 2026-06-26 01:55 UTCGHSA enrichment
  42. 2026-06-25 17:48 UTCNVD updateCVSS v3 → 6.1
  43. 2026-06-25 02:32 UTCGHSA enrichment
  44. 2026-06-24 14:05 UTCEPSS rescore
  45. 2026-06-24 03:10 UTCGHSA enrichment
  46. 2026-06-23 21:33 UTCEPSS rescore
  47. 2026-06-23 21:33 UTCEPSS rescore
  48. 2026-06-23 03:46 UTCEG score recompute
  49. 2026-06-23 03:45 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-55655?
CVE-2026-55655 is a medium vulnerability published on June 23, 2026. A flaw was found in OpenSSH. A local unprivileged attacker on a Linux client host can hijack client-side X11 forwarding connections. This is possible by pre-binding the preferred abstract X socket name when X11 forwarding is enabled and a local UNIX-domain X socket is used. A successful attack can…
When was CVE-2026-55655 disclosed?
CVE-2026-55655 was first published in the National Vulnerability Database on June 23, 2026, with the most recent update on July 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55655 actively exploited?
CVE-2026-55655 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 99.5% of all scored CVEs.
What is the CVSS score of CVE-2026-55655?
CVE-2026-55655 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-55655?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55655, 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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