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
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.8Exploit: None knownExposed: 0

A fix is available — apply it.

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 PROB
0%
EPSS %ILE
16%
KEV
Not listed

Published

May 6, 2026

Last Modified

August 5, 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(13)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-virtual-6.8 (6.8.0-134.134) @ noble2026-08-23ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1058.61.1) @ noble2026-08-23ubuntu
ubuntulinux-tools-lowlatency-hwe-20.04-edge (6.8.0-134.134.1) @ noble2026-08-23ubuntu
ubuntulinux-tools-nvidia-tegra-rt-6.8 (6.8.0-1029.30) @ noble2026-08-23ubuntu
ubuntulinux-xilinx-zynqmp (6.8.0.1032.33) @ noble2026-08-23ubuntu
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2049.50) @ noble2026-08-23ubuntu
ubuntulinux-tools-raspi-6.8 (6.8.0-1060.64) @ noble2026-08-23ubuntu
ubuntulinux-tools-fips-6.8 (6.8.0-134.134+fips1) @ noble2026-08-23ubuntu
ubuntulinux-tools-azure-edge (6.8.0-1063.71~22.04.1) @ jammy2026-08-23ubuntu
ubuntulinux-tools-azure-fde-lts-24.04 (6.8.0-1062.69) @ noble2026-08-23ubuntu
ubuntulinux-tools-azure-fde-6.8 (6.8.0-1062.69~22.04.1) @ jammy2026-08-23ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.8.0-136.136~22.04.1) @ jammy2026-08-23ubuntu
linuxKernel @ 6.12.75—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.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 7.2~rc5-1~exp1 (496 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 7.2~rc7-1~exp1 (350 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.85-1~bpo12+1 (17 versions)6.12.85-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 6.19~rc8-1~exp1 (116 versions)6.19.6-1—

Weakness Classification(1)

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

All Vendor Advisories

(12)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 5× in last 7d / 27× 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 227 total refreshes for this CVE.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-17 19:31 UTCEPSS rescore
  3. 2026-09-16 14:08 UTCEPSS rescore
  4. 2026-09-16 05:15 UTCEPSS rescore
  5. 2026-09-13 16:47 UTCEPSS rescore
  6. 2026-09-12 15:01 UTCEPSS rescore
  7. 2026-09-11 16:23 UTCOSV refresh
  8. 2026-09-11 14:53 UTCEPSS rescore
  9. 2026-09-11 09:37 UTCEPSS rescore
  10. 2026-09-10 09:34 UTCEPSS rescore
  11. 2026-09-08 22:00 UTCEPSS rescore
  12. 2026-09-07 16:01 UTCEPSS rescore
  13. 2026-09-06 13:47 UTCEPSS rescore
  14. 2026-09-04 05:06 UTCEPSS rescore
  15. 2026-09-02 14:12 UTCEPSS rescore
  16. 2026-09-01 13:54 UTCEPSS rescore
  17. 2026-08-30 19:17 UTCEPSS rescore
  18. 2026-08-30 01:22 UTCEPSS rescore
  19. 2026-08-28 21:41 UTCEPSS rescore
  20. 2026-08-27 14:25 UTCEPSS rescore
  21. 2026-08-26 14:46 UTCEPSS rescore
  22. 2026-08-25 13:49 UTCEPSS rescore
  23. 2026-08-23 19:54 UTCEG score recompute
  24. 2026-08-23 19:54 UTCVendor advisory
  25. 2026-08-23 19:54 UTCGHSA enrichment
Show 75 more
  1. 2026-08-23 00:19 UTCEPSS rescore
  2. 2026-08-21 23:49 UTCEPSS rescore
  3. 2026-08-20 22:55 UTCEPSS rescore
  4. 2026-08-19 17:04 UTCEPSS rescore
  5. 2026-08-18 13:48 UTCEPSS rescore
  6. 2026-08-17 13:47 UTCEPSS rescore
  7. 2026-08-17 12:54 UTCEG score recompute
  8. 2026-08-17 12:54 UTCVendor advisory
  9. 2026-08-17 12:54 UTCGHSA enrichment
  10. 2026-08-16 14:56 UTCEPSS rescore
  11. 2026-08-16 04:52 UTCEG score recompute
  12. 2026-08-16 04:52 UTCVendor advisory
  13. 2026-08-16 04:52 UTCGHSA enrichment
  14. 2026-08-16 02:14 UTCEPSS rescore
  15. 2026-08-15 01:56 UTCEG score recompute
  16. 2026-08-15 01:56 UTCVendor advisory
  17. 2026-08-15 01:56 UTCGHSA enrichment
  18. 2026-08-15 01:30 UTCEPSS rescore
  19. 2026-08-14 14:41 UTCVendor advisory
  20. 2026-08-14 14:41 UTCGHSA enrichment
  21. 2026-08-14 03:26 UTCEG score recompute
  22. 2026-08-14 03:26 UTCVendor advisory
  23. 2026-08-14 03:26 UTCGHSA enrichment
  24. 2026-08-13 22:00 UTCEPSS rescore
  25. 2026-08-13 04:15 UTCVendor advisory
  26. 2026-08-13 04:15 UTCGHSA enrichment
  27. 2026-08-12 17:00 UTCEG score recompute
  28. 2026-08-12 17:00 UTCVendor advisory
  29. 2026-08-12 17:00 UTCGHSA enrichment
  30. 2026-08-12 13:51 UTCEPSS rescore
  31. 2026-08-11 16:00 UTCEG score recompute
  32. 2026-08-11 16:00 UTCVendor advisory
  33. 2026-08-11 16:00 UTCGHSA enrichment
  34. 2026-08-11 13:43 UTCEPSS rescore
  35. 2026-08-11 01:31 UTCEG score recompute
  36. 2026-08-11 01:31 UTCVendor advisory
  37. 2026-08-11 01:31 UTCGHSA enrichment
  38. 2026-08-11 00:00 UTCEPSS rescore
  39. 2026-08-10 12:44 UTCVendor advisory
  40. 2026-08-10 12:44 UTCGHSA enrichment
  41. 2026-08-10 01:05 UTCVendor advisory
  42. 2026-08-10 01:05 UTCGHSA enrichment
  43. 2026-08-09 13:50 UTCEG score recompute
  44. 2026-08-09 13:50 UTCVendor advisory
  45. 2026-08-09 13:50 UTCGHSA enrichment
  46. 2026-08-09 13:46 UTCEPSS rescore
  47. 2026-08-09 02:34 UTCEG score recompute
  48. 2026-08-09 02:34 UTCVendor advisory
  49. 2026-08-09 02:34 UTCGHSA enrichment
  50. 2026-08-08 16:37 UTCEPSS rescore
  51. 2026-08-08 11:43 UTCVendor advisory
  52. 2026-08-08 11:43 UTCGHSA enrichment
  53. 2026-08-08 00:24 UTCEG score recompute
  54. 2026-08-08 00:24 UTCVendor advisory
  55. 2026-08-08 00:24 UTCGHSA enrichment
  56. 2026-08-07 13:09 UTCVendor advisory
  57. 2026-08-07 13:09 UTCGHSA enrichment
  58. 2026-08-07 01:54 UTCVendor advisory
  59. 2026-08-07 01:53 UTCGHSA enrichment
  60. 2026-08-06 12:26 UTCVendor advisory
  61. 2026-08-06 12:26 UTCGHSA enrichment
  62. 2026-08-06 01:06 UTCEG score recompute
  63. 2026-08-06 01:06 UTCVendor advisory
  64. 2026-08-06 01:06 UTCGHSA enrichment
  65. 2026-08-05 19:17 UTCEPSS rescore
  66. 2026-08-05 13:51 UTCEG score recompute
  67. 2026-08-05 13:51 UTCVendor advisory
  68. 2026-08-05 13:51 UTCGHSA enrichment
  69. 2026-08-04 15:10 UTCEPSS rescore
  70. 2026-08-04 10:38 UTCEPSS rescore
  71. 2026-08-03 19:52 UTCEG score recompute
  72. 2026-08-03 19:52 UTCVendor advisory
  73. 2026-08-03 19:52 UTCGHSA enrichment
  74. 2026-08-03 10:36 UTCEPSS rescore
  75. 2026-08-03 03:59 UTCVendor advisory

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 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-2026-43249 actively exploited?
CVE-2026-43249 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 84.4% of all scored CVEs.
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

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