CVE-2026-64449

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-25. a secondary CVSS source baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: None knownExposed: 0

A fix is available — apply it.

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

staging: vme_user: bound slave read/write to the kern_buf size

The SLAVE-path helpers buffer_to_user() and buffer_from_user() copy 'count' bytes into/out of the fixed-size kern_buf (size_buf == PCI_BUF_SIZE == 0x20000, 128 KiB) using *ppos as the offset, without bounding *ppos + count against size_buf.

vme_user_write()/vme_user_read() only clamp count to the VME window size (image_size = vme_get_size(resource)), which VME_SET_SLAVE sets from the user-supplied slave.size -- validated against the VME address space (up to VME_A32_MAX = 4 GiB), not against PCI_BUF_SIZE. When the window exceeds 128 KiB, a write()/read() copies past the kern_buf allocation.

Clamp count against size_buf in both helpers, with an early return when *ppos is already at/after the buffer end. *ppos is >= 0 here (the caller rejects negative offsets), so size_buf - *ppos cannot wrap. This mirrors the existing clamp in the MASTER-path helpers resource_to_user() / resource_from_user(), and matches the read()/write() convention of a short transfer at end-of-buffer.

Found by static analysis (CodeQL taint tracking + CBMC bounded model checking) and confirmed dynamically under KASAN with the vme_fake bridge:

BUG: KASAN: slab-out-of-bounds in _copy_from_user+0x2d/0x80 Write of size 262144 at addr ffff888004100000 by task trigger/68 _copy_from_user+0x2d/0x80 vme_user_write+0x13e/0x240 [vme_user] vfs_write+0x1b8/0x7a0 ksys_write+0xb8/0x150

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity78% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
4%
KEV
Not listed

Published

July 25, 2026

Last Modified

September 3, 2026

Advisory Details (6)

Auto-updated Jul 27, 2026
No patch confirmed yet.
generic

staging: vme_user: bound slave read/write to the kern_buf size - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e99f2df433c63c86c93de1e5f08f16e404388756
generic

staging: vme_user: bound slave read/write to the kern_buf size - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/adc8b9c30d716c362646edb45662aa1c641a154a
generic

staging: vme_user: bound slave read/write to the kern_buf size - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9f32f38265014fac7f5dc9490fb01a638ce6e121
generic

staging: vme_user: bound slave read/write to the kern_buf size - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8eff7cd4817e14dbe3b9952cce55ef52d1d38940
generic

staging: vme_user: bound slave read/write to the kern_buf size - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/65358d89dc9f1c25d9364b2b3ef0f3b47717f9ed
generic

staging: vme_user: bound slave read/write to the kern_buf size - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1b495fa0d4927c88d88bf346bf311f2e26e860ed

Vendor Advisories for CVE-2026-64449(2)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-gcp-edge (7.0.0-1011.11~24.04.1) @ noble2026-09-15ubuntu
ubuntulinux-virtual-hwe-26.04-edge (7.0.0-31.31) @ resolute2026-09-15ubuntu
ubuntulinux-tools-oem-7.0 (7.0.0-1013.13) @ resolute2026-09-15ubuntu

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

(6 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 7.2~rc5-1~exp1 (500 versions)——
linux-6.16.1.106-3~deb11u1 ... 6.1.177-1~deb11u1 (22 versions)6.1.180-1~deb11u1—
Debian:12(2)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (55 versions)6.1.180-1—
linux-6.12—6.12.100-1~deb12u1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.95-1~bpo12+1 (30 versions)6.12.96-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (158 versions)7.1.4-1—

Weakness Classification(1)

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

All Vendor Advisories

(3)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 26× in last 7d / 103× 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 194 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-64449?
CVE-2026-64449 is a high vulnerability published on July 25, 2026. In the Linux kernel, the following vulnerability has been resolved: staging: vmeuser: bound slave read/write to the kernbuf size The SLAVE-path helpers buffertouser() and bufferfromuser() copy 'count' bytes into/out of the fixed-size kernbuf (sizebuf == PCIBUFSIZE == 0x20000, 128 KiB) using *ppos…
When was CVE-2026-64449 disclosed?
CVE-2026-64449 was first published in the National Vulnerability Database on July 25, 2026, with the most recent update on September 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-64449 actively exploited?
CVE-2026-64449 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 96.4% of all scored CVEs.
What is the CVSS score of CVE-2026-64449?
CVE-2026-64449 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-64449?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-64449, 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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