CVE-2025-21766

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2025-02-27. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 5.5Exploit: None knownExposed: 0

A fix is available — apply it.

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

ipv4: use RCU protection in __ip_rt_update_pmtu()

__ip_rt_update_pmtu() must use RCU protection to make sure the net structure it reads does not disappear.

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%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
41%
KEV
Not listed

Published

February 27, 2025

Last Modified

August 5, 2026

Advisory Details (8)

Auto-updated Aug 2, 2026
⚠️ Active exploitation confirmed. Patch available.
generic🔴 Active Exploitation

SSA-082556

https://cert-portal.siemens.com/productcert/html/ssa-082556.html
generic Patch Available

[SECURITY] [DLA 4102-1] linux-6.1 security update

https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html
generic

ipv4: use RCU protection in __ip_rt_update_pmtu() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ea07480b23225942208f1b754fea1e7ec486d37e
generic

ipv4: use RCU protection in __ip_rt_update_pmtu() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ce3c6165fce0f06305c806696882a3ad4b90e33f
generic

ipv4: use RCU protection in __ip_rt_update_pmtu() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a39f61d212d822b3062d7f70fa0588e50e55664e
generic

ipv4: use RCU protection in __ip_rt_update_pmtu() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9b1766d1ff5fe496aabe9fc5f4e34e53f35c11c4
generic

ipv4: use RCU protection in __ip_rt_update_pmtu() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4583748b65dee4d61bd50a2214715b4237bc152a
generic

ipv4: use RCU protection in __ip_rt_update_pmtu() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/139512191bd06f1b496117c76372b2ce372c9a41

Patch Availability(24)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-gcp-fips (5.15.0.1083.73) @ jammy2026-05-21ubuntu
ubuntulinux-virtual-hwe-24.04-edge (6.11.0-26.26) @ oracular2026-05-21ubuntu
ubuntulinux-tools-gcp-lts-22.04 (5.15.0.1083.79) @ jammy2026-05-21ubuntu
ubuntulinux-tools-gcp-edge (5.15.0.1083.92~20.04.1) @ focal2026-05-21ubuntu
ubuntulinux-tools-aws-edge (5.15.0.1084.91~20.04.1) @ focal2026-05-21ubuntu
ubuntulinux-virtual-hwe-20.04-edge (5.15.0.142.152~20.04.1) @ focal2026-05-21ubuntu
ubuntulinux-xilinx-zynqmp-tools-host (5.15.0-1050.54) @ jammy2026-05-21ubuntu
ubuntulinux-tools-fips (5.15.0.140.80) @ jammy2026-05-21ubuntu
ubuntulinux-virtual-hwe-20.04-edge (5.15.0.140.135) @ jammy2026-05-21ubuntu
ubuntulinux-tools-ibm-lts-24.04 (6.8.0-1033.33) @ noble2026-05-21ubuntu
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2028.29) @ noble2026-05-21ubuntu
ubuntulinux-tools-nvidia-tegra-rt (5.15.0.1037.37) @ jammy2026-05-21ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.8.0-78.78~22.04.1) @ jammy2026-05-21ubuntu
ubuntulinux-tools-oracle-lts-24.04 (6.8.0-1032.33) @ noble2026-05-21ubuntu
ubuntulinux-tools-azure-nvidia-lts-24.04 (6.8.0-1022.23) @ noble2026-05-21ubuntu
ubuntulinux-tools-gke-5.15 (5.15.0.1081.80) @ jammy2026-05-21ubuntu
ubuntulinux-tools-aws-fips (5.15.0.1084.80) @ jammy2026-05-21ubuntu
ubuntulinux-tools-realtime (5.15.0.1084.88) @ jammy2026-05-21ubuntu
ubuntulinux-tools-azure-fips (5.15.0.1089.74) @ jammy2026-05-21ubuntu
ubuntulinux-tools-aws (6.11.0-1014.15) @ oracular2026-05-21ubuntu
ubuntulinux-tools-oracle-64k (6.11.0-1016.17) @ oracular2026-05-21ubuntu
ubuntulinux-virtual-6.8 (6.8.0-78.78) @ noble2026-05-21ubuntu
ubuntulinux-tools-raspi-nolpae (5.15.0.1078.76) @ jammy2026-05-21ubuntu
linuxKernel @ 5.15.179—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.

All Vendor Advisories

(23)

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 10× 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.

Showing the most recent 100 of 148 total refreshes for this CVE.

  1. 2026-08-07 16:26 UTCEPSS rescore
  2. 2026-08-06 13:46 UTCEPSS rescore
  3. 2026-08-05 19:16 UTCEPSS rescore
  4. 2026-08-05 14:03 UTCEG score recompute
  5. 2026-08-05 14:03 UTCVendor advisory
  6. 2026-08-05 14:03 UTCGHSA enrichment
  7. 2026-08-04 15:09 UTCEPSS rescore
  8. 2026-08-04 10:37 UTCEPSS rescore
  9. 2026-08-03 10:35 UTCEPSS rescore
  10. 2026-08-02 02:25 UTCEPSS rescore
  11. 2026-08-01 04:15 UTCEPSS rescore
  12. 2026-07-30 16:27 UTCEPSS rescore
  13. 2026-07-30 07:21 UTCEG score recompute
  14. 2026-07-30 07:21 UTCGHSA enrichment
  15. 2026-07-30 06:24 UTCNVD updateCVSS v3 → 5.5 · severity → MEDIUM
  16. 2026-07-30 01:29 UTCEPSS rescore
  17. 2026-07-28 15:35 UTCEPSS rescore
  18. 2026-07-28 01:24 UTCOSV refresh
  19. 2026-07-27 14:12 UTCEPSS rescore
  20. 2026-07-26 14:53 UTCEPSS rescore
  21. 2026-07-25 14:17 UTCEPSS rescore
  22. 2026-07-24 14:17 UTCEPSS rescore
  23. 2026-07-23 14:17 UTCEPSS rescore
  24. 2026-07-23 02:50 UTCEG score recompute
  25. 2026-07-22 14:07 UTCEPSS rescore
Show 75 more
  1. 2026-07-22 14:07 UTCEPSS rescore
  2. 2026-07-21 15:24 UTCEPSS rescore
  3. 2026-07-20 17:07 UTCEPSS rescore
  4. 2026-07-19 14:30 UTCEPSS rescore
  5. 2026-07-19 14:30 UTCEPSS rescore
  6. 2026-07-19 02:28 UTCEPSS rescore
  7. 2026-07-19 02:28 UTCEPSS rescore
  8. 2026-07-18 10:03 UTCEPSS rescore
  9. 2026-07-16 17:02 UTCEPSS rescore
  10. 2026-07-15 01:59 UTCEPSS rescore
  11. 2026-07-14 13:11 UTCMITRE cvelistV5
  12. 2026-07-13 22:29 UTCEPSS rescore
  13. 2026-07-13 22:29 UTCEPSS rescore
  14. 2026-07-13 06:12 UTCEPSS rescore
  15. 2026-07-13 06:12 UTCEPSS rescore
  16. 2026-07-12 05:46 UTCEPSS rescore
  17. 2026-07-12 05:46 UTCEPSS rescore
  18. 2026-07-11 08:27 UTCEPSS rescore
  19. 2026-07-11 08:26 UTCEPSS rescore
  20. 2026-07-10 17:41 UTCOSV refresh
  21. 2026-07-09 19:09 UTCEPSS rescore
  22. 2026-07-08 15:14 UTCEPSS rescore
  23. 2026-07-07 13:45 UTCEPSS rescore
  24. 2026-07-06 16:26 UTCEPSS rescore
  25. 2026-07-06 02:22 UTCEPSS rescore
  26. 2026-07-06 02:22 UTCEPSS rescore
  27. 2026-07-05 02:30 UTCEPSS rescore
  28. 2026-07-04 06:30 UTCEPSS rescore
  29. 2026-07-01 15:06 UTCEPSS rescore
  30. 2026-06-30 23:21 UTCEPSS rescore
  31. 2026-06-30 23:21 UTCEPSS rescore
  32. 2026-06-29 14:06 UTCEPSS rescore
  33. 2026-06-28 14:07 UTCEPSS rescore
  34. 2026-06-28 14:07 UTCEPSS rescore
  35. 2026-06-28 04:55 UTCEPSS rescore
  36. 2026-06-28 04:55 UTCEPSS rescore
  37. 2026-06-27 03:08 UTCEPSS rescore
  38. 2026-06-27 03:08 UTCEPSS rescore
  39. 2026-06-25 13:49 UTCEPSS rescore
  40. 2026-06-25 13:49 UTCEPSS rescore
  41. 2026-06-24 14:04 UTCEPSS rescore
  42. 2026-06-24 14:04 UTCEPSS rescore
  43. 2026-06-23 21:32 UTCEPSS rescore
  44. 2026-06-23 21:32 UTCEPSS rescore
  45. 2026-06-22 14:25 UTCEPSS rescore
  46. 2026-06-22 14:25 UTCEPSS rescore
  47. 2026-06-22 01:37 UTCOSV refresh
  48. 2026-06-21 14:56 UTCEPSS rescore
  49. 2026-06-21 14:56 UTCEPSS rescore
  50. 2026-06-21 01:59 UTCEPSS rescore
  51. 2026-06-21 01:59 UTCEPSS rescore
  52. 2026-06-19 19:25 UTCEPSS rescore
  53. 2026-06-19 19:25 UTCEPSS rescore
  54. 2026-06-18 17:52 UTCEPSS rescore
  55. 2026-06-18 17:52 UTCEPSS rescore
  56. 2026-06-17 17:52 UTCEPSS rescore
  57. 2026-06-16 17:52 UTCEPSS rescore
  58. 2026-06-16 17:52 UTCEPSS rescore
  59. 2026-06-15 17:48 UTCEPSS rescore
  60. 2026-06-14 23:17 UTCEPSS rescore
  61. 2026-06-13 22:59 UTCEPSS rescore
  62. 2026-06-12 23:11 UTCEPSS rescore
  63. 2026-06-11 13:59 UTCEPSS rescore
  64. 2026-06-10 22:18 UTCEPSS rescore
  65. 2026-06-10 13:22 UTCEPSS rescore
  66. 2026-06-08 14:16 UTCEPSS rescore
  67. 2026-06-08 14:16 UTCEPSS rescore
  68. 2026-06-07 15:24 UTCEPSS rescore
  69. 2026-06-07 15:24 UTCEPSS rescore
  70. 2026-06-06 13:47 UTCEPSS rescore
  71. 2026-06-06 13:47 UTCEPSS rescore
  72. 2026-06-05 22:46 UTCEPSS rescore
  73. 2026-06-05 22:46 UTCEPSS rescore
  74. 2026-06-05 06:10 UTCEPSS rescore
  75. 2026-06-05 06:10 UTCEPSS rescore

Related CVEs(same product + same vendor)

Frequently asked(5)

What is CVE-2025-21766?
CVE-2025-21766 is a medium vulnerability published on February 27, 2025. In the Linux kernel, the following vulnerability has been resolved: ipv4: use RCU protection in iprtupdate_pmtu() iprtupdate_pmtu() must use RCU protection to make sure the net structure it reads does not disappear.
When was CVE-2025-21766 disclosed?
CVE-2025-21766 was first published in the National Vulnerability Database on February 27, 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-2025-21766 actively exploited?
CVE-2025-21766 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 58.6% of all scored CVEs.
What is the CVSS score of CVE-2025-21766?
CVE-2025-21766 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2025-21766?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-21766, 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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