CVE-2026-43249

HIGHNVD 8.88.8
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-05-06. NVD baseline CVSS 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
8.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.8Exploit: NoneExposed: 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:

9p/xen: protect xen_9pfs_front_free against concurrent calls

The xenwatch thread can race with other back-end change notifications and call xen_9pfs_front_free() twice, hitting the observed general protection fault due to a double-free. Guard the teardown path so only one caller can release the front-end state at a time, preventing the crash.

This is a fix for the following double-free:

[ 27.052347] Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] SMP DEBUG_PAGEALLOC NOPTI [ 27.052357] CPU: 0 UID: 0 PID: 32 Comm: xenwatch Not tainted 6.18.0-02087-g51ab33fc0a8b-dirty #60 PREEMPT(none) [ 27.052363] RIP: e030:xen_9pfs_front_free+0x1d/0x150 [ 27.052368] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 41 55 41 54 55 48 89 fd 48 c7 c7 48 d0 92 85 53 e8 cb cb 05 00 48 8b 45 08 48 8b 55 00 <48> 3b 28 0f 85 f9 28 35 fe 48 3b 6a 08 0f 85 ef 28 35 fe 48 89 42 [ 27.052377] RSP: e02b:ffffc9004016fdd0 EFLAGS: 00010246 [ 27.052381] RAX: 6b6b6b6b6b6b6b6b RBX: ffff88800d66e400 RCX: 0000000000000000 [ 27.052385] RDX: 6b6b6b6b6b6b6b6b RSI: 0000000000000000 RDI: 0000000000000000 [ 27.052389] RBP: ffff88800a887040 R08: 0000000000000000 R09: 0000000000000000 [ 27.052393] R10: 0000000000000000 R11: 0000000000000000 R12: ffff888009e46b68 [ 27.052397] R13: 0000000000000200 R14: 0000000000000000 R15: ffff88800a887040 [ 27.052404] FS: 0000000000000000(0000) GS:ffff88808ca57000(0000) knlGS:0000000000000000 [ 27.052408] CS: e030 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 27.052412] CR2: 00007f9714004360 CR3: 0000000004834000 CR4: 0000000000050660 [ 27.052418] Call Trace: [ 27.052420] [ 27.052422] xen_9pfs_front_changed+0x5d5/0x720 [ 27.052426] ? xenbus_otherend_changed+0x72/0x140 [ 27.052430] ? __pfx_xenwatch_thread+0x10/0x10 [ 27.052434] xenwatch_thread+0x94/0x1c0 [ 27.052438] ? __pfx_autoremove_wake_function+0x10/0x10 [ 27.052442] kthread+0xf8/0x240 [ 27.052445] ? __pfx_kthread+0x10/0x10 [ 27.052449] ? __pfx_kthread+0x10/0x10 [ 27.052452] ret_from_fork+0x16b/0x1a0 [ 27.052456] ? __pfx_kthread+0x10/0x10 [ 27.052459] ret_from_fork_asm+0x1a/0x30 [ 27.052463] [ 27.052465] Modules linked in: [ 27.052471] ---[ end trace 0000000000000000 ]---

CVSS v3
8.8
EG Score
8.8(medium)
EG Risk
44(Track)
EG Risk 44/100SSVC: 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
Severity88% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
15.4%
KEV
Not listed

Published

May 6, 2026

Last Modified

May 11, 2026

Advisory Details (4)

Auto-updated May 11, 2026
No patch confirmed yet.
generic

9p/xen: protect xen_9pfs_front_free against concurrent calls - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ce8ded2e61f47747e31eeefb44dc24a2160a7e32
generic

9p/xen: protect xen_9pfs_front_free against concurrent calls - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/bf841d43f7a33d75675ba7f4e214ac1c67913065
generic

9p/xen: protect xen_9pfs_front_free against concurrent calls - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a5d00dff97118a32fcf5fec7a4c3f864c4620c4e
generic

9p/xen: protect xen_9pfs_front_free against concurrent calls - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/59e7707492576bdbfa8c1dbe7d90791df31e4773

Vendor Advisories for CVE-2026-43249(1)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
linuxKernel @ 6.12.75osv

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.

Data Freshness Timeline

(refreshed 9× in last 7d / 31× 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 112 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-43249?
CVE-2026-43249 is a high vulnerability published on May 6, 2026. In the Linux kernel, the following vulnerability has been resolved: 9p/xen: protect xen9pfsfront_free against concurrent calls The xenwatch thread can race with other back-end change notifications and call xen9pfsfront_free() twice, hitting the observed general protection fault due to a…
When was CVE-2026-43249 disclosed?
CVE-2026-43249 was first published in the National Vulnerability Database on May 6, 2026, with the most recent update on May 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43249 actively exploited?
CVE-2026-43249 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 15.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-43249?
CVE-2026-43249 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-43249?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43249, 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-2026-43249

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