CVE-2025-21954

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2025-04-01. 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:

netmem: prevent TX of unreadable skbs

Currently on stable trees we have support for netmem/devmem RX but not TX. It is not safe to forward/redirect an RX unreadable netmem packet into the device's TX path, as the device may call dma-mapping APIs on dma addrs that should not be passed to it.

Fix this by preventing the xmit of unreadable skbs.

Tested by configuring tc redirect:

sudo tc qdisc add dev eth1 ingress sudo tc filter add dev eth1 ingress protocol ip prio 1 flower ip_proto \ tcp src_ip 192.168.1.12 action mirred egress redirect dev eth1

Before, I see unreadable skbs in the driver's TX path passed to dma mapping APIs.

After, I don't see unreadable skbs in the driver's TX path passed to dma mapping APIs.

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
41%
KEV
Not listed

Published

April 1, 2025

Last Modified

August 5, 2026

Advisory Details (3)

Auto-updated Jul 30, 2026
No patch confirmed yet.
generic

netmem: prevent TX of unreadable skbs - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f3600c867c99a2cc8038680ecf211089c50e7971
generic

netmem: prevent TX of unreadable skbs - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/454825019d2f0c59e5174ece9e713f45ad80beff
generic

netmem: prevent TX of unreadable skbs - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1c17c8ced25c5fbe424c7ad7ea11d33014a986b1

Vendor Advisories for CVE-2025-21954(1)

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

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatkernel-0:6.12.0-124.8.1.el10_12025-11-11redhat
linuxKernel @ 6.12.20—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

(2 across 2 ecosystems)
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux—6.12.20-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux—6.12.20-1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 5× in last 7d / 28× 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 149 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2025-21954?
CVE-2025-21954 is a medium vulnerability published on April 1, 2025. In the Linux kernel, the following vulnerability has been resolved: netmem: prevent TX of unreadable skbs Currently on stable trees we have support for netmem/devmem RX but not TX. It is not safe to forward/redirect an RX unreadable netmem packet into the device's TX path, as the device may call…
When was CVE-2025-21954 disclosed?
CVE-2025-21954 was first published in the National Vulnerability Database on April 1, 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-2025-21954 actively exploited?
CVE-2025-21954 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 59.2% of all scored CVEs.
What is the CVSS score of CVE-2025-21954?
CVE-2025-21954 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2025-21954?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-21954, 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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