CVE-2026-63952

HIGHPre-NVD 8.48.4—
EchelonGraph scoreMEDIUM confidence

Score 8.4 from GitHub Security Advisory (severity: HIGH) published 2026-07-19. the CNA's CVSS baseline 8.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
Trending — 4 sources updated this week
8.4EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.4Exploit: None knownExposed: 0

A fix is available — apply it.

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

memfd: deny writeable mappings when implying SEAL_WRITE

When SEAL_EXEC is added, SEAL_WRITE is implied to make W^X. But the implied seal is set after the check that makes sure the memfd can not have any writable mappings. This means one can use SEAL_EXEC to apply SEAL_WRITE while having writeable mappings.

This breaks the contract that SEAL_WRITE provides and can be used by an attacker to pass a memfd that appears to be write sealed but can still be modified arbitrarily.

Fix this by adding the implied seals before the call for mapping_deny_writable() is done.

CVSS v3
8.4
EG Score
8.4(medium)
EG Risk
42(Track)
EG Risk 42/100SSVC: 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
Severity84% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

July 19, 2026

Last Modified

August 5, 2026

Advisory Details (5)

Auto-updated Jul 20, 2026
No patch confirmed yet.
generic

memfd: deny writeable mappings when implying SEAL_WRITE - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b3f4f82d1315f1439059a83d1c22c51a5b43d99e
generic

memfd: deny writeable mappings when implying SEAL_WRITE - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/555702282d4536a865dfffb1cd4f6028f196e7e8
generic

memfd: deny writeable mappings when implying SEAL_WRITE - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3be2a24f7f72ad7321ed6ad1715b956a4527bcf4
generic

memfd: deny writeable mappings when implying SEAL_WRITE - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3b041514cb6eae45869b020f743c14d983363222
generic

memfd: deny writeable mappings when implying SEAL_WRITE - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0995d1f79aed8ccbf62056189dd53fd19726ea08

Vendor Advisories for CVE-2026-63952(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)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-oracle-7.0 (7.0.0-1008.8) @ resolute2026-08-30ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1016.16) @ resolute2026-08-30ubuntu
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-08-30ubuntu
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1015.15) @ resolute2026-08-30ubuntu
ubuntulinux-tools-nvidia-hwe-26.04 (7.0.0-2016.16) @ resolute2026-08-30ubuntu
redhatkernel-0:5.14.0-687.41.1.el9_82026-08-20redhat
redhatkernel-0:6.12.0-211.49.1.el10_22026-08-20redhat

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

(2 across 2 ecosystems)
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.94-1~bpo12+1 (27 versions)6.12.94-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.0.9-1~bpo13+1 (138 versions)7.0.12-1—

Additional Vendor Advisories

(6)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 30× in last 7d / 157× 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 204 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-63952?
CVE-2026-63952 is a high vulnerability published on July 19, 2026. In the Linux kernel, the following vulnerability has been resolved: memfd: deny writeable mappings when implying SEAL_WRITE When SEALEXEC is added, SEALWRITE is implied to make W^X. But the implied seal is set after the check that makes sure the memfd can not have any writable mappings. This means…
When was CVE-2026-63952 disclosed?
CVE-2026-63952 was first published in the National Vulnerability Database on July 19, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63952 actively exploited?
CVE-2026-63952 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 94.1% of all scored CVEs.
What is the CVSS score of CVE-2026-63952?
CVE-2026-63952 has a CVSS v4.0 base score of 8.4 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-63952?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63952, 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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