CVE-2025-21866

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2025-03-12. 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:

powerpc/code-patching: Fix KASAN hit by not flagging text patching area as VM_ALLOC

Erhard reported the following KASAN hit while booting his PowerMac G4 with a KASAN-enabled kernel 6.13-rc6:

BUG: KASAN: vmalloc-out-of-bounds in copy_to_kernel_nofault+0xd8/0x1c8 Write of size 8 at addr f1000000 by task chronyd/1293

CPU: 0 UID: 123 PID: 1293 Comm: chronyd Tainted: G W 6.13.0-rc6-PMacG4 #2 Tainted: [W]=WARN Hardware name: PowerMac3,6 7455 0x80010303 PowerMac Call Trace: [c2437590] [c1631a84] dump_stack_lvl+0x70/0x8c (unreliable) [c24375b0] [c0504998] print_report+0xdc/0x504 [c2437610] [c050475c] kasan_report+0xf8/0x108 [c2437690] [c0505a3c] kasan_check_range+0x24/0x18c [c24376a0] [c03fb5e4] copy_to_kernel_nofault+0xd8/0x1c8 [c24376c0] [c004c014] patch_instructions+0x15c/0x16c [c2437710] [c00731a8] bpf_arch_text_copy+0x60/0x7c [c2437730] [c0281168] bpf_jit_binary_pack_finalize+0x50/0xac [c2437750] [c0073cf4] bpf_int_jit_compile+0xb30/0xdec [c2437880] [c0280394] bpf_prog_select_runtime+0x15c/0x478 [c24378d0] [c1263428] bpf_prepare_filter+0xbf8/0xc14 [c2437990] [c12677ec] bpf_prog_create_from_user+0x258/0x2b4 [c24379d0] [c027111c] do_seccomp+0x3dc/0x1890 [c2437ac0] [c001d8e0] system_call_exception+0x2dc/0x420 [c2437f30] [c00281ac] ret_from_syscall+0x0/0x2c --- interrupt: c00 at 0x5a1274 NIP: 005a1274 LR: 006a3b3c CTR: 005296c8 REGS: c2437f40 TRAP: 0c00 Tainted: G W (6.13.0-rc6-PMacG4) MSR: 0200f932 CR: 24004422 XER: 00000000

GPR00: 00000166 af8f3fa0 a7ee3540 00000001 00000000 013b6500 005a5858 0200f932 GPR08: 00000000 00001fe9 013d5fc8 005296c8 2822244c 00b2fcd8 00000000 af8f4b57 GPR16: 00000000 00000001 00000000 00000000 00000000 00000001 00000000 00000002 GPR24: 00afdbb0 00000000 00000000 00000000 006e0004 013ce060 006e7c1c 00000001 NIP [005a1274] 0x5a1274 LR [006a3b3c] 0x6a3b3c --- interrupt: c00

The buggy address belongs to the virtual mapping at [f1000000, f1002000) created by: text_area_cpu_up+0x20/0x190

The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:00000000 index:0x0 pfn:0x76e30 flags: 0x80000000(zone=2) raw: 80000000 00000000 00000122 00000000 00000000 00000000 ffffffff 00000001 raw: 00000000 page dumped because: kasan: bad access detected

Memory state around the buggy address: f0ffff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f0ffff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >f1000000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ f1000080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f1000100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ==================================================================

f8 corresponds to KASAN_VMALLOC_INVALID which means the area is not initialised hence not supposed to be used yet.

Powerpc text patching infrastructure allocates a virtual memory area using get_vm_area() and flags it as VM_ALLOC. But that flag is meant to be used for vmalloc() and vmalloc() allocated memory is not supposed to be used before a call to __vmalloc_node_range() which is never called for that area.

That went undetected until commit e4137f08816b ("mm, kasan, kmsan: instrument copy_from/to_kernel_nofault")

The area allocated by text_area_cpu_up() is not vmalloc memory, it is mapped directly on demand when needed by map_kernel_page(). There is no VM flag corresponding to such usage, so just pass no flag. That way the area will be unpoisonned and usable immediately.

CVSS v3
5.5
EG Score
5.5(medium)
EG Risk
25(Track)
EG Risk 25/100SSVC: 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%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
11.6%
KEV
Not listed

Published

March 12, 2025

Last Modified

November 3, 2025

References (9)

Vendor Advisories for CVE-2025-21866(1)

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

Patch Availability(30)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-fips (5.15.0.140.80) @ jammy2026-05-30ubuntu
ubuntulinux-virtual-hwe-20.04-edge (5.15.0.140.135) @ jammy2026-05-30ubuntu
ubuntulinux-tools-gcp-lts-22.04 (5.15.0.1083.79) @ jammy2026-05-30ubuntu
ubuntulinux-tools-gcp-fips (5.15.0.1083.73) @ jammy2026-05-30ubuntu
ubuntulinux-virtual-hwe-18.04-edge (5.4.0.216.208) @ focal2026-05-30ubuntu
ubuntulinux-tools-gcp-edge (5.15.0.1083.92~20.04.1) @ focal2026-05-30ubuntu
ubuntulinux-tools-aws (6.11.0-1014.15) @ oracular2026-05-30ubuntu
ubuntulinux-tools-nvidia-tegra-rt (5.15.0.1037.37) @ jammy2026-05-30ubuntu
ubuntulinux-virtual-hwe-24.04-edge (6.11.0-26.26) @ oracular2026-05-30ubuntu
ubuntulinux-tools-azure-fips (5.15.0.1089.74) @ jammy2026-05-30ubuntu
ubuntulinux-tools-azure-fips (5.4.0.1151.88) @ focal2026-05-30ubuntu
ubuntulinux-tools-gcp-fips (5.4.0.1149.91) @ focal2026-05-30ubuntu
ubuntulinux-xilinx-zynqmp-tools-5.4.0-1064 (5.4.0-1064.68) @ focal2026-05-30ubuntu
ubuntulinux-tools-realtime (5.15.0.1084.88) @ jammy2026-05-30ubuntu
ubuntulinux-tools-ibm-edge (5.4.0.1092.97~18.04.1) @ bionic2026-05-30ubuntu
ubuntulinux-tools-gke-5.15 (5.15.0.1081.80) @ jammy2026-05-30ubuntu
ubuntulinux-tools-kvm (5.4.0.1133.129) @ focal2026-05-30ubuntu
ubuntulinux-tools-oracle-edge (5.4.0.1144.154~18.04.1) @ bionic2026-05-30ubuntu
ubuntulinux-virtual-hwe-18.04-edge (5.4.0.216.236~18.04.1) @ bionic2026-05-30ubuntu
ubuntulinux-xilinx-zynqmp-tools-host (5.15.0-1050.54) @ jammy2026-05-30ubuntu
ubuntulinux-tools-iot (5.4.0.1051.49) @ focal2026-05-30ubuntu
ubuntulinux-virtual-6.8 (6.8.0-78.78) @ noble2026-05-30ubuntu
ubuntulinux-tools-aws-fips (5.15.0.1084.80) @ jammy2026-05-30ubuntu
ubuntulinux-tools-aws-edge (5.4.0.1146.156~18.04.1) @ bionic2026-05-30ubuntu
ubuntulinux-tools-raspi-nolpae (5.15.0.1078.76) @ jammy2026-05-30ubuntu
ubuntulinux-tools-oracle-64k (6.11.0-1016.17) @ oracular2026-05-30ubuntu
ubuntulinux-virtual-hwe-20.04-edge (5.15.0.142.152~20.04.1) @ focal2026-05-30ubuntu
ubuntulinux-tools-fips (5.4.0.1120.117) @ focal2026-05-30ubuntu
ubuntulinux-tools-ibm-lts-20.04 (5.4.0.1092.121) @ focal2026-05-30ubuntu
ubuntulinux-tools-aws-edge (5.15.0.1084.91~20.04.1) @ focal2026-05-30ubuntu

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.

Weakness Classification(1)

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

Additional Vendor Advisories

(24)

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2025-21866?
CVE-2025-21866 is a medium vulnerability published on March 12, 2025. In the Linux kernel, the following vulnerability has been resolved: powerpc/code-patching: Fix KASAN hit by not flagging text patching area as VM_ALLOC Erhard reported the following KASAN hit while booting his PowerMac G4 with a KASAN-enabled kernel 6.13-rc6: BUG: KASAN: vmalloc-out-of-bounds in…
When was CVE-2025-21866 disclosed?
CVE-2025-21866 was first published in the National Vulnerability Database on March 12, 2025, with the most recent update on November 3, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-21866 actively exploited?
CVE-2025-21866 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 11.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2025-21866?
CVE-2025-21866 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2025-21866?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-21866, 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-2025-21866

Explore →

Is Your Infrastructure Affected by CVE-2025-21866?

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

Start Free Scan →Browse All CVEs