CVE-2026-55655

MEDIUMNVD 6.15.0▼
EchelonGraph scoreMEDIUM confidence

Score 5.0 from GitHub Security Advisory published 2026-06-23. NVD baseline CVSS 6.1; sources differ by 1.1.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
6.1
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.1Exploit: NoneExposed: 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
5.0(medium)
EG Risk
—
EPSS
0.6%
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 7× in last 7d / 66× 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. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:25 UTCEPSS rescore
  3. 2026-07-20 17:08 UTCEPSS rescore
  4. 2026-07-18 10:04 UTCEPSS rescore
  5. 2026-07-16 17:03 UTCEPSS rescore
  6. 2026-07-16 13:35 UTCVendor advisory
  7. 2026-07-16 13:35 UTCGHSA enrichment
  8. 2026-07-15 16:57 UTCEPSS rescore
  9. 2026-07-15 16:57 UTCEPSS rescore
  10. 2026-07-15 14:07 UTCVendor advisory
  11. 2026-07-15 14:07 UTCGHSA enrichment
  12. 2026-07-14 14:26 UTCVendor advisory
  13. 2026-07-14 14:26 UTCGHSA enrichment
  14. 2026-07-13 22:31 UTCEPSS rescore
  15. 2026-07-13 15:04 UTCVendor advisory
  16. 2026-07-13 15:04 UTCGHSA enrichment
  17. 2026-07-12 15:36 UTCVendor advisory
  18. 2026-07-12 15:36 UTCGHSA enrichment
  19. 2026-07-12 05:46 UTCEPSS rescore
  20. 2026-07-11 16:07 UTCVendor advisory
  21. 2026-07-11 16:07 UTCGHSA enrichment
  22. 2026-07-10 16:45 UTCVendor advisory
  23. 2026-07-10 16:45 UTCGHSA enrichment
  24. 2026-07-09 19:10 UTCEPSS rescore
  25. 2026-07-09 19:10 UTCEPSS rescore
Show 41 more
  1. 2026-07-09 17:23 UTCVendor advisory
  2. 2026-07-09 17:23 UTCGHSA enrichment
  3. 2026-07-08 17:58 UTCGHSA enrichment
  4. 2026-07-08 15:16 UTCEPSS rescore
  5. 2026-07-08 15:16 UTCEPSS rescore
  6. 2026-07-08 14:36 UTCNVD updateCVSS v3 → 6.1
  7. 2026-07-07 18:35 UTCGHSA enrichment
  8. 2026-07-07 13:46 UTCEPSS rescore
  9. 2026-07-07 13:46 UTCEPSS rescore
  10. 2026-07-06 19:11 UTCGHSA enrichment
  11. 2026-07-06 16:27 UTCEPSS rescore
  12. 2026-07-06 16:27 UTCEPSS rescore
  13. 2026-07-05 19:49 UTCGHSA enrichment
  14. 2026-07-04 20:27 UTCGHSA enrichment
  15. 2026-07-04 06:31 UTCEPSS rescore
  16. 2026-07-04 06:31 UTCEPSS rescore
  17. 2026-07-03 22:01 UTCMITRE cvelistV5CVSS v3 → 5
  18. 2026-07-03 21:05 UTCGHSA enrichment
  19. 2026-07-02 21:43 UTCGHSA enrichment
  20. 2026-07-01 22:21 UTCGHSA enrichment
  21. 2026-07-01 15:07 UTCEPSS rescore
  22. 2026-06-30 22:45 UTCGHSA enrichment
  23. 2026-06-29 23:23 UTCGHSA enrichment
  24. 2026-06-29 14:06 UTCEPSS rescore
  25. 2026-06-29 14:06 UTCEPSS rescore
  26. 2026-06-29 00:02 UTCGHSA enrichment
  27. 2026-06-28 14:07 UTCEPSS rescore
  28. 2026-06-28 04:56 UTCEPSS rescore
  29. 2026-06-28 04:56 UTCEPSS rescore
  30. 2026-06-28 00:39 UTCGHSA enrichment
  31. 2026-06-27 03:08 UTCEPSS rescore
  32. 2026-06-27 01:16 UTCGHSA enrichment
  33. 2026-06-26 01:55 UTCGHSA enrichment
  34. 2026-06-25 17:48 UTCNVD updateCVSS v3 → 6.1
  35. 2026-06-25 02:32 UTCGHSA enrichment
  36. 2026-06-24 14:05 UTCEPSS rescore
  37. 2026-06-24 03:10 UTCGHSA enrichment
  38. 2026-06-23 21:33 UTCEPSS rescore
  39. 2026-06-23 21:33 UTCEPSS rescore
  40. 2026-06-23 03:46 UTCEG score recompute
  41. 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 0.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-55655?
CVE-2026-55655 has a CVSS v3 base score of 6.1 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 5.0.
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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