CVE-2025-37949

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2025-05-20. 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

A fix is available — apply it.

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

xenbus: Use kref to track req lifetime

Marek reported seeing a NULL pointer fault in the xenbus_thread callstack: BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: e030:__wake_up_common+0x4c/0x180 Call Trace: __wake_up_common_lock+0x82/0xd0 process_msg+0x18e/0x2f0 xenbus_thread+0x165/0x1c0

process_msg+0x18e is req->cb(req). req->cb is set to xs_wake_up(), a thin wrapper around wake_up(), or xenbus_dev_queue_reply(). It seems like it was xs_wake_up() in this case.

It seems like req may have woken up the xs_wait_for_reply(), which kfree()ed the req. When xenbus_thread resumes, it faults on the zero-ed data.

Linux Device Drivers 2nd edition states: "Normally, a wake_up call can cause an immediate reschedule to happen, meaning that other processes might run before wake_up returns." ... which would match the behaviour observed.

Change to keeping two krefs on each request. One for the caller, and one for xenbus_thread. Each will kref_put() when finished, and the last will free it.

This use of kref matches the description in Documentation/core-api/kref.rst

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
10%
KEV
Not listed

Published

May 20, 2025

Last Modified

August 5, 2026

Advisory Details (10)

Auto-updated Aug 2, 2026
Patch available.
generic Patch Available

[SECURITY] [DLA 4327-1] linux security update

https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
generic Patch Available

[SECURITY] [DLA 4271-1] linux-6.1 security update

https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html
generic

xenbus: Use kref to track req lifetime - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f1bcac367bc95631afbb918348f30dec887d0e1b
generic

xenbus: Use kref to track req lifetime - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/cbfaf46b88a4c01b64c4186cdccd766c19ae644c
generic

xenbus: Use kref to track req lifetime - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8e9c8a0393b5f85f1820c565ab8105660f4e8f92
generic

xenbus: Use kref to track req lifetime - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8b02f85e84dc6f7c150cef40ddb69af5a25659e5
generic

xenbus: Use kref to track req lifetime - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4d260a5558df4650eb87bc41b2c9ac2d6b2ba447
generic

xenbus: Use kref to track req lifetime - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2466b0f66795c3c426cacc8998499f38031dbb59
generic

xenbus: Use kref to track req lifetime - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1f0304dfd9d217c2f8b04a9ef4b3258a66eedd27
generic

xenbus: Use kref to track req lifetime - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0e94a246bb6d9538010b6c02d2b1d4717a97b2e5

Patch Availability(30)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-xilinx-zynqmp-tools-host (5.15.0-1052.56) @ jammy2026-05-30ubuntu
ubuntulinux-tools-gcp-fips-5.15 (5.15.0.1087.77) @ jammy2026-05-30ubuntu
ubuntulinux-tools-kvm-5.15 (5.15.0.1084.80) @ jammy2026-05-30ubuntu
ubuntulinux-tools-intel-iotg-edge (5.15.0.1083.89~20.04.1) @ focal2026-05-30ubuntu
ubuntulinux-tools-raspi-nolpae (5.15.0.1083.81) @ jammy2026-05-30ubuntu
ubuntulinux-virtual-hwe-20.04-edge (5.15.0.144.141) @ jammy2026-05-30ubuntu
ubuntulinux-tools-gcp-edge (6.8.0-1047.50~22.04.2) @ jammy2026-05-30ubuntu
ubuntulinux-tools-azure-lts-22.04 (5.15.0.1094.92) @ jammy2026-05-30ubuntu
ubuntulinux-tools-azure-edge (5.15.0.1094.103~20.04.1) @ focal2026-05-30ubuntu
ubuntulinux-tools-azure-6.14 (6.14.0-1010.10) @ plucky2026-05-30ubuntu
ubuntulinux-virtual-6.8 (6.8.0-100.100) @ noble2026-05-30ubuntu
ubuntulinux-tools-azure-fips-5.15 (5.15.0.1094.79) @ jammy2026-05-30ubuntu
ubuntulinux-tools-realtime-6.8.1 (6.8.1-1041.42) @ noble2026-05-30ubuntu
ubuntulinux-tools-fips-6.8 (6.8.0-100.100+fips1) @ noble2026-05-30ubuntu
ubuntulinux-tools-oracle-lts-24.04 (6.8.0-1043.44) @ noble2026-05-30ubuntu
ubuntulinux-tools-gcp-fips-6.8 (6.8.0-1047.50+fips1) @ noble2026-05-30ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1046.52+fips1) @ noble2026-05-30ubuntu
ubuntulinux-tools-azure-edge (6.8.0-1051.57~22.04.1) @ jammy2026-05-30ubuntu
ubuntulinux-xilinx-zynqmp (6.8.0.1023.24) @ noble2026-05-30ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.8.0-100.100~22.04.1) @ jammy2026-05-30ubuntu
ubuntulinux-tools-realtime-5.15 (5.15.0.1088.92) @ jammy2026-05-30ubuntu
ubuntulinux-tools-gke-64k-6.8 (6.8.0-1043.48) @ noble2026-05-30ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1046.49.1) @ noble2026-05-30ubuntu
ubuntulinux-tools-lowlatency-hwe-20.04-edge (6.8.0-100.100.1) @ noble2026-05-30ubuntu
ubuntulinux-tools-ibm-lts-24.04 (6.8.0-1044.44) @ noble2026-05-30ubuntu
ubuntulinux-virtual-hwe-24.04-edge (6.14.0-28.28) @ plucky2026-05-30ubuntu
ubuntulinux-virtual-hwe-24.04-edge (6.14.0-28.28~24.04.1) @ noble2026-05-30ubuntu
ubuntulinux-tools-realtime-hwe-22.04 (6.8.1-1041.42~22.04.1) @ jammy2026-05-30ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1046.52) @ noble2026-05-30ubuntu
linuxKernel @ 5.4.294—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

(5 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (46 versions)5.10.244-1—
linux-6.16.1.106-3~deb11u1 ... 6.1.137-1~deb11u1 (8 versions)6.1.140-1~deb11u1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (40 versions)6.1.140-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux—6.12.29-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux—6.12.29-1—

Weakness Classification(1)

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

All Vendor Advisories

(25)

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 / 22× 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 148 total refreshes for this CVE.

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

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2025-37949?
CVE-2025-37949 is a medium vulnerability published on May 20, 2025. In the Linux kernel, the following vulnerability has been resolved: xenbus: Use kref to track req lifetime Marek reported seeing a NULL pointer fault in the xenbus_thread callstack: BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: e030:wakeupcommon+0x4c/0x180 Call Trace: <TASK>…
When was CVE-2025-37949 disclosed?
CVE-2025-37949 was first published in the National Vulnerability Database on May 20, 2025, 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-2025-37949 actively exploited?
CVE-2025-37949 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 89.7% of all scored CVEs.
What is the CVSS score of CVE-2025-37949?
CVE-2025-37949 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2025-37949?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-37949, 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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