CVE-2025-39775

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2025-09-11. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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

mm/mremap: fix WARN with uffd that has remap events disabled

Registering userfaultd on a VMA that spans at least one PMD and then mremap()'ing that VMA can trigger a WARN when recovering from a failed page table move due to a page table allocation error.

The code ends up doing the right thing (recurse, avoiding moving actual page tables), but triggering that WARN is unpleasant:

WARNING: CPU: 2 PID: 6133 at mm/mremap.c:357 move_normal_pmd mm/mremap.c:357 [inline] WARNING: CPU: 2 PID: 6133 at mm/mremap.c:357 move_pgt_entry mm/mremap.c:595 [inline] WARNING: CPU: 2 PID: 6133 at mm/mremap.c:357 move_page_tables+0x3832/0x44a0 mm/mremap.c:852 Modules linked in: CPU: 2 UID: 0 PID: 6133 Comm: syz.0.19 Not tainted 6.17.0-rc1-syzkaller-00004-g53e760d89498 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:move_normal_pmd mm/mremap.c:357 [inline] RIP: 0010:move_pgt_entry mm/mremap.c:595 [inline] RIP: 0010:move_page_tables+0x3832/0x44a0 mm/mremap.c:852 Code: ... RSP: 0018:ffffc900037a76d8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000032930007 RCX: ffffffff820c6645 RDX: ffff88802e56a440 RSI: ffffffff820c7201 RDI: 0000000000000007 RBP: ffff888037728fc0 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000032930007 R11: 0000000000000000 R12: 0000000000000000 R13: ffffc900037a79a8 R14: 0000000000000001 R15: dffffc0000000000 FS: 000055556316a500(0000) GS:ffff8880d68bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30863fff CR3: 0000000050171000 CR4: 0000000000352ef0 Call Trace: copy_vma_and_data+0x468/0x790 mm/mremap.c:1215 move_vma+0x548/0x1780 mm/mremap.c:1282 mremap_to+0x1b7/0x450 mm/mremap.c:1406 do_mremap+0xfad/0x1f80 mm/mremap.c:1921 __do_sys_mremap+0x119/0x170 mm/mremap.c:1977 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f00d0b8ebe9 Code: ... RSP: 002b:00007ffe5ea5ee98 EFLAGS: 00000246 ORIG_RAX: 0000000000000019 RAX: ffffffffffffffda RBX: 00007f00d0db5fa0 RCX: 00007f00d0b8ebe9 RDX: 0000000000400000 RSI: 0000000000c00000 RDI: 0000200000000000 RBP: 00007ffe5ea5eef0 R08: 0000200000c00000 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000002 R13: 00007f00d0db5fa0 R14: 00007f00d0db5fa0 R15: 0000000000000005

The underlying issue is that we recurse during the original page table move, but not during the recovery move.

Fix it by checking for both VMAs and performing the check before the pmd_none() sanity check.

Add a new helper where we perform+document that check for the PMD and PUD level.

Thanks to Harry for bisecting.

CVSS v3
5.5
EG Score
5.5(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: 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
Severity55% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
2%
KEV
Not listed

Published

September 11, 2025

Last Modified

November 25, 2025

References (2)

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
linuxKernel @ 6.16.4—osv

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.

Data Freshness Timeline

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

Frequently asked(5)

What is CVE-2025-39775?
CVE-2025-39775 is a medium vulnerability published on September 11, 2025. In the Linux kernel, the following vulnerability has been resolved: mm/mremap: fix WARN with uffd that has remap events disabled Registering userfaultd on a VMA that spans at least one PMD and then mremap()'ing that VMA can trigger a WARN when recovering from a failed page table move due to a page…
When was CVE-2025-39775 disclosed?
CVE-2025-39775 was first published in the National Vulnerability Database on September 11, 2025, with the most recent update on November 25, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-39775 actively exploited?
CVE-2025-39775 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 97.9% of all scored CVEs.
What is the CVSS score of CVE-2025-39775?
CVE-2025-39775 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2025-39775?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-39775, 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

Explore the affected products and dependency analysis for CVE-2025-39775

Explore →

Is Your Infrastructure Affected by CVE-2025-39775?

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

Start Free Scan →Browse All CVEs