CVE-2026-64558

HIGHPre-NVD 7.87.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-29. A secondary CVSS source baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source

Also known asEUVD-2026-50405 (ENISA EUVD) · GHSA-82p5-pf6r-jcxr (GitHub Security Advisories)Source: ENISA EUVD

7.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 7.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

s390/pkey: Check length in pkey_pckmo handler implementation

Explicitly check the length of the target buffer in the pkey_pckmo implementation of the key_to_protkey() handler function. The handler function fails, if the generated output data exceeds the length of the provided target buffer.

CVSS v3
7.8
EG Score
7.8HIGHmedium confidence
EG Risk
35
EG Risk 35/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity78% × 45%
Impact severity (EG Severity): CVSS 7.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.1% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.1%
EPSS %ILE
1st
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.

EG Severity
7.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.1% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-09). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

July 29, 2026

Last Modified

November 3, 2026

Advisory Details (4)

Auto-updated Jul 30, 2026
Patch available.
Web page

s390/pkey: Check length in pkey_pckmo handler implementation - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/614aa0491c7a190556c2345dddee0b6f5ed90989
Web page

s390/pkey: Check length in pkey_pckmo handler implementation - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/433e5e70cdc1edf382d28d08a885b22e2b98b7da
Web page

s390/pkey: Check length in pkey_pckmo handler implementation - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1ac287e2af9a9112fe271427ef45eceb26bce8b4
Web page

s390/pkey: Check length in pkey_pckmo handler implementation - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/02028a24e26d85262ab9c8fc4344e1f3503007fc

Vendor Advisories for CVE-2026-64558(2)

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

Patch Availability(7)

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

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux-6.12—
  • every version up to 6.12.100-1~deb12u1: fixed in 6.12.100-1~deb12u1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.96-1 (31 versions)
  • every version up to 6.12.100-1: fixed in 6.12.100-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (163 versions)
  • every version up to 7.1.5-1: fixed in 7.1.5-1
—

Weakness Classification(1)

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

Additional Vendor Advisories

(6)

Data Freshness Timeline

(refreshed 8× in last 7d / 41× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 279 rows on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 179 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  2. 2026-11-11 16:40 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  3. 2026-11-10 16:45 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  4. 2026-11-10 03:14 UTCEchelonGraph re-scored
  5. 2026-11-10 03:14 UTCVendor advisory
  6. 2026-11-10 03:14 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  7. 2026-11-08 16:40 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  8. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  9. 2026-11-06 16:39 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  10. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  11. 2026-11-04 16:36 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  12. 2026-11-03 18:28 UTCEchelonGraph re-scored
  13. 2026-11-03 18:28 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  14. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  15. 2026-11-03 02:24 UTCEchelonGraph re-scored
  16. 2026-11-03 02:24 UTCVendor advisory
  17. 2026-11-03 02:24 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  18. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  19. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  20. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  21. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  22. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  23. 2026-10-27 17:38 UTCEchelonGraph re-scored
  24. 2026-10-27 17:38 UTCVendor advisory
  25. 2026-10-27 17:37 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
Show 75 more
  1. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  2. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  3. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  4. 2026-10-25 14:12 UTCEchelonGraph re-scored
  5. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  6. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  7. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  8. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  9. 2026-10-19 21:42 UTCEchelonGraph re-scored
  10. 2026-10-19 21:42 UTCVendor advisory
  11. 2026-10-19 21:41 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  12. 2026-10-19 20:54 UTCEchelonGraph re-scored
  13. 2026-10-19 20:54 UTCVendor advisory
  14. 2026-10-19 20:54 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  15. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  16. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  17. 2026-10-18 03:22 UTCEchelonGraph re-scored
  18. 2026-10-16 17:36 UTCEchelonGraph re-scored
  19. 2026-10-16 17:36 UTCVendor advisory
  20. 2026-10-16 17:35 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  21. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  22. 2026-10-16 16:09 UTCEchelonGraph re-scored
  23. 2026-10-16 16:09 UTCVendor advisory
  24. 2026-10-16 16:09 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  25. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  26. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  27. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  28. 2026-10-13 11:39 UTCEchelonGraph re-scored
  29. 2026-10-13 11:39 UTCVendor advisory
  30. 2026-10-13 11:39 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  31. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  32. 2026-10-12 15:47 UTCEchelonGraph re-scored
  33. 2026-10-11 19:32 UTCEchelonGraph re-scored
  34. 2026-10-11 16:47 UTCEchelonGraph re-scored
  35. 2026-10-11 14:09 UTCEchelonGraph re-scored
  36. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  37. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  38. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  39. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  40. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  41. 2026-10-07 00:01 UTCEchelonGraph re-scored
  42. 2026-10-07 00:01 UTCVendor advisory
  43. 2026-10-07 00:00 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  44. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  45. 2026-10-05 20:51 UTCEchelonGraph re-scored
  46. 2026-10-05 20:51 UTCVendor advisory
  47. 2026-10-05 20:51 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  48. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  49. 2026-10-05 02:36 UTCEchelonGraph re-scored
  50. 2026-10-05 02:36 UTCVendor advisory
  51. 2026-10-05 02:36 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  52. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  53. 2026-10-04 07:01 UTCEchelonGraph re-scored
  54. 2026-10-04 07:01 UTCVendor advisory
  55. 2026-10-04 07:01 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  56. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  57. 2026-10-02 17:57 UTCEchelonGraph re-scored
  58. 2026-10-02 17:57 UTCVendor advisory
  59. 2026-10-02 17:57 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  60. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  61. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  62. 2026-10-01 15:43 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  63. 2026-10-01 03:34 UTCEchelonGraph re-scored
  64. 2026-10-01 03:34 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  65. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  66. 2026-09-29 07:35 UTCEchelonGraph re-scored
  67. 2026-09-29 07:35 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  68. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  69. 2026-09-28 07:43 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  70. 2026-09-27 19:38 UTCEchelonGraph re-scored
  71. 2026-09-27 19:37 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  72. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  73. 2026-09-25 05:38 UTCEchelonGraph re-scored
  74. 2026-09-25 05:38 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8
  75. 2026-09-24 09:54 UTCGHSA enrichmentGHSA-82p5-pf6r-jcxr · GitHub severity HIGH · GitHub CVSS 7.8

Frequently asked(5)

What is CVE-2026-64558?
CVE-2026-64558 is a high-severity vulnerability; its CVE record was published on July 29, 2026. In the Linux kernel, the following vulnerability has been resolved: s390/pkey: Check length in pkey_pckmo handler implementation Explicitly check the length of the target buffer in the pkey_pckmo implementation of the key_to_protkey() handler function. The handler function fails, if the generated…
When was the CVE record for CVE-2026-64558 published?
The CVE record for CVE-2026-64558 was published on July 29, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of November 3, 2026; the record at its source may have been updated since.
Is CVE-2026-64558 actively exploited?
CVE-2026-64558 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (1st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-64558?
CVE-2026-64558 has a CVSS base score of 7.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-64558?
A fix for CVE-2026-64558 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-64558 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-64558

Explore →

Is Your Infrastructure Affected by CVE-2026-64558?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.