CVE-2026-64309

MEDIUMNVD 5.55.5
EchelonGraph scoreMEDIUM confidence

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

Score 5.5 from GitHub Security Advisory published 2026-07-25. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
5.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 5.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

crypto: ccp - Do not initialize SNP for ioctl(SNP_COMMIT)

Sashiko notes:

> if SEV initialization fails and KVM is actively running normal VMs, could a > userspace process trigger this code path via /dev/sev ioctls (e.g., > SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN > execution for an active VM trigger a general protection fault and crash the > host?

The SNP_COMMIT command does not require the firmware to be in any particular state. Skip initializing it if it was previously uninitialized.

The SEV-SNP firmware specification doc 56860 does not mention SNP_COMMIT in Table 5 as a command that is allowed in the UNINIT state, but it is in fact allowed and a future documentation update will reflect that.

CVSS v3
5.5
EG Score
5.5MEDIUMmedium confidence
EG Risk
25
EG Risk 25/100

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)
Severity55% × 45%
Impact severity (EG Severity): CVSS 5.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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
0.2%
EPSS %ILE
5th
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 (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.

EG Severity
5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-17). 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: 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 (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” 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 25, 2026

Last Modified

September 4, 2026

Advisory Details (4)

Auto-updated Sep 4, 2026
Patch available.
Web page

crypto: ccp - Do not initialize SNP for ioctl(SNP_COMMIT) - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/7a361c74bb12f3398c388905f1d325be642cd36e
Web page

crypto: ccp - Do not initialize SNP for ioctl(SNP_COMMIT) - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/74768f73854d647a6462f252dc8782ab8a835211
Web page

crypto: ccp - Do not initialize SNP for ioctl(SNP_COMMIT) - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/67ed191b4c8bdf432a3f32d1eb302880b4795cd1
Web page

crypto: ccp - Do not initialize SNP for ioctl(SNP_COMMIT) - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5a1364da2f04217a36e2fdfa2db4ee025b383a20

Vendor Advisories for CVE-2026-64309(1)

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

Patch Availability(11)

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 ... 6.12.95-1~bpo12+1 (30 versions)
  • every version up to 6.12.96-1: fixed in 6.12.96-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (159 versions)
  • every version up to 7.1.4-1: fixed in 7.1.4-1
—

Weakness Classification(1)

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

All Vendor Advisories

(11)

Data Freshness Timeline

(refreshed 8× in last 7d / 53× 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 it from the CNA feed. 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). Most recent first.

Showing the most recent 100 of 162 refreshes 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 62 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  2. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  3. 2026-10-18 03:22 UTCEG score recompute
  4. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  5. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  6. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  7. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  8. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  9. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  10. 2026-10-12 15:48 UTCEG score recompute
  11. 2026-10-11 19:32 UTCEG score recompute
  12. 2026-10-11 16:47 UTCEG score recompute
  13. 2026-10-11 14:09 UTCEG score recompute
  14. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  15. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  16. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  17. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  18. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  19. 2026-10-07 06:19 UTCEG score recompute
  20. 2026-10-07 06:19 UTCVendor advisory
  21. 2026-10-07 06:19 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  22. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  23. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  24. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  25. 2026-10-04 07:38 UTCEG score recompute
Show 75 more
  1. 2026-10-04 07:38 UTCVendor advisory
  2. 2026-10-04 07:37 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  3. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  4. 2026-10-02 19:36 UTCEG score recompute
  5. 2026-10-02 19:36 UTCVendor advisory
  6. 2026-10-02 19:36 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  7. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  8. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  9. 2026-10-01 04:26 UTCEG score recompute
  10. 2026-10-01 04:26 UTCVendor advisory
  11. 2026-10-01 04:26 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  12. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  13. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  14. 2026-09-28 04:20 UTCEG score recompute
  15. 2026-09-28 04:20 UTCVendor advisory
  16. 2026-09-28 04:20 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  17. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  18. 2026-09-25 09:54 UTCEG score recompute
  19. 2026-09-25 09:54 UTCVendor advisory
  20. 2026-09-25 09:53 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  21. 2026-09-23 22:11 UTCEG score recompute
  22. 2026-09-23 22:11 UTCVendor advisory
  23. 2026-09-23 22:10 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  24. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  25. 2026-09-22 22:05 UTCEG score recompute
  26. 2026-09-22 22:05 UTCVendor advisory
  27. 2026-09-22 22:05 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  28. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  29. 2026-09-20 01:34 UTCEG score recompute
  30. 2026-09-20 01:34 UTCVendor advisory
  31. 2026-09-20 01:34 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  32. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  33. 2026-09-18 08:59 UTCEG score recompute
  34. 2026-09-18 08:59 UTCVendor advisory
  35. 2026-09-18 08:59 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  36. 2026-09-17 09:13 UTCEG score recompute
  37. 2026-09-17 09:13 UTCVendor advisory
  38. 2026-09-17 09:13 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  39. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  40. 2026-09-16 06:35 UTCEG score recompute
  41. 2026-09-16 06:35 UTCVendor advisory
  42. 2026-09-16 06:35 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  43. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  44. 2026-09-14 15:54 UTCEG score recompute
  45. 2026-09-14 15:54 UTCVendor advisory
  46. 2026-09-14 15:54 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  47. 2026-09-13 15:57 UTCVendor advisory
  48. 2026-09-13 15:57 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  49. 2026-09-12 16:13 UTCEG score recompute
  50. 2026-09-12 16:13 UTCVendor advisory
  51. 2026-09-12 16:13 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  52. 2026-09-11 16:28 UTCEG score recompute
  53. 2026-09-11 16:28 UTCVendor advisory
  54. 2026-09-11 16:28 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  55. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  56. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  57. 2026-09-10 13:29 UTCEG score recompute
  58. 2026-09-10 13:29 UTCVendor advisory
  59. 2026-09-10 13:29 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  60. 2026-09-09 08:39 UTCEG score recompute
  61. 2026-09-09 08:39 UTCVendor advisory
  62. 2026-09-09 08:39 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  63. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  64. 2026-09-07 21:19 UTCEG score recompute
  65. 2026-09-07 21:19 UTCVendor advisory
  66. 2026-09-07 21:19 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  67. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  68. 2026-09-06 19:13 UTCEG score recompute
  69. 2026-09-06 19:13 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  70. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  71. 2026-09-05 19:21 UTCEG score recompute
  72. 2026-09-05 19:21 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4 · GitHub CVSS 5.5
  73. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  74. 2026-09-04 13:13 UTCEG score recomputeFirst assessed: 5.5 MEDIUM
  75. 2026-09-04 13:13 UTCGHSA enrichmentGHSA-8w5v-46pm-6rg4

Frequently asked(5)

What is CVE-2026-64309?
CVE-2026-64309 is a medium-severity vulnerability; its CVE record was published on July 25, 2026. In the Linux kernel, the following vulnerability has been resolved: crypto: ccp - Do not initialize SNP for ioctl(SNP_COMMIT) Sashiko notes: if SEV initialization fails and KVM is actively running normal VMs, could a userspace process trigger this code path via /dev/sev ioctls (e.g., SEVPDHGEN) and…
When was the CVE record for CVE-2026-64309 published?
The CVE record for CVE-2026-64309 was published on July 25, 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 September 4, 2026; the record at its source may have been updated since.
Is CVE-2026-64309 actively exploited?
CVE-2026-64309 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (5th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-64309?
CVE-2026-64309 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-64309?
A fix for CVE-2026-64309 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-64309 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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