CVE-2025-21696

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2025-02-12. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.5Exploit: NoneExposed: 0

A fix is available — apply it.

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

mm: clear uffd-wp PTE/PMD state on mremap()

When mremap()ing a memory region previously registered with userfaultfd as write-protected but without UFFD_FEATURE_EVENT_REMAP, an inconsistency in flag clearing leads to a mismatch between the vma flags (which have uffd-wp cleared) and the pte/pmd flags (which do not have uffd-wp cleared). This mismatch causes a subsequent mprotect(PROT_WRITE) to trigger a warning in page_table_check_pte_flags() due to setting the pte to writable while uffd-wp is still set.

Fix this by always explicitly clearing the uffd-wp pte/pmd flags on any such mremap() so that the values are consistent with the existing clearing of VM_UFFD_WP. Be careful to clear the logical flag regardless of its physical form; a PTE bit, a swap PTE bit, or a PTE marker. Cover PTE, huge PMD and hugetlb paths.

CVSS v3
5.5
EG Score
5.5(medium)
EG Risk
—
EPSS
8.6%
KEV
Not listed

Published

February 12, 2025

Last Modified

October 1, 2025

References (2)

Vendor Advisories for CVE-2025-21696(3)

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

Patch Availability(4)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-virtual-hwe-24.04-edge (6.11.0-24.24+1) @ oracular2026-05-30ubuntu
ubuntulinux-tools-azure (6.11.0-1013.13) @ oracular2026-05-30ubuntu
redhatkernel-0:6.12.0-124.8.1.el10_12025-11-11redhat
redhatkernel-0:5.14.0-611.5.1.el9_72025-11-11redhat

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.

Additional Vendor Advisories

(2)

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

Frequently asked(5)

What is CVE-2025-21696?
CVE-2025-21696 is a medium vulnerability published on February 12, 2025. In the Linux kernel, the following vulnerability has been resolved: mm: clear uffd-wp PTE/PMD state on mremap() When mremap()ing a memory region previously registered with userfaultfd as write-protected but without UFFDFEATUREEVENT_REMAP, an inconsistency in flag clearing leads to a mismatch…
When was CVE-2025-21696 disclosed?
CVE-2025-21696 was first published in the National Vulnerability Database on February 12, 2025, with the most recent update on October 1, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-21696 actively exploited?
CVE-2025-21696 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 8.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2025-21696?
CVE-2025-21696 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2025-21696?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-21696, 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.

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