CVE-2025-21765

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
5.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.5Exploit: NoneExposed: 0

A fix is available — apply it.

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

ipv6: use RCU protection in ip6_default_advmss()

ip6_default_advmss() needs rcu protection to make sure the net structure it reads does not disappear.

CVSS v3
5.5
EG Score
5.5(medium)
EG Risk
—
EPSS
12.0%
KEV
Not listed

Published

February 27, 2025

Last Modified

July 14, 2026

Advisory Details (10)

Auto-updated Jul 17, 2026
Patch available.
generic Patch Available

[SECURITY] [DLA 4178-1] linux security update

https://lists.debian.org/debian-lts-announce/2025/05/msg00030.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

ipv6: use RCU protection in ip6_default_advmss() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d02f30d220ef9511568a48dba8a9004c65f8d904
generic

ipv6: use RCU protection in ip6_default_advmss() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/84212387caadb211cd9dadd6fd5563bd37dc1f5e
generic

ipv6: use RCU protection in ip6_default_advmss() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/78ad057472d8c76e0602402269222f9f9c698790
generic

ipv6: use RCU protection in ip6_default_advmss() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/713a40c892f40300d63691d9f85b2a23b48fe1e8
generic

ipv6: use RCU protection in ip6_default_advmss() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/550ed693f47370502a71b85382e7f9e6417300b8
generic

ipv6: use RCU protection in ip6_default_advmss() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4176a68b0db8fc74ac14fcd00ba8231371051dc2
generic

ipv6: use RCU protection in ip6_default_advmss() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3c8ffcd248da34fc41e52a46e51505900115fc2a
generic

ipv6: use RCU protection in ip6_default_advmss() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/28de355b63ad42309ed5a03ee7c436c90512265b

Vendor Advisories for CVE-2025-21765(3)

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

Patch Availability(31)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-fips (5.15.0.140.80) @ jammy2026-05-21ubuntu
ubuntulinux-tools-gcp-fips (5.15.0.1083.73) @ jammy2026-05-21ubuntu
ubuntulinux-tools-gcp-lts-22.04 (5.15.0.1083.79) @ jammy2026-05-21ubuntu
ubuntulinux-virtual-hwe-18.04-edge (5.4.0.216.208) @ focal2026-05-21ubuntu
ubuntulinux-tools-aws (6.11.0-1014.15) @ oracular2026-05-21ubuntu
ubuntulinux-virtual-hwe-18.04-edge (5.4.0.216.236~18.04.1) @ bionic2026-05-21ubuntu
ubuntulinux-tools-azure-fips (5.4.0.1151.88) @ focal2026-05-21ubuntu
ubuntulinux-tools-ibm-lts-20.04 (5.4.0.1092.121) @ focal2026-05-21ubuntu
ubuntulinux-xilinx-zynqmp-tools-5.4.0-1064 (5.4.0-1064.68) @ focal2026-05-21ubuntu
ubuntulinux-tools-kvm (5.4.0.1133.129) @ focal2026-05-21ubuntu
ubuntulinux-virtual-hwe-24.04-edge (6.11.0-26.26) @ oracular2026-05-21ubuntu
ubuntulinux-tools-ibm-edge (5.4.0.1092.97~18.04.1) @ bionic2026-05-21ubuntu
ubuntulinux-tools-oracle-edge (5.4.0.1144.154~18.04.1) @ bionic2026-05-21ubuntu
ubuntulinux-tools-oracle-lts-24.04 (6.8.0-1032.33) @ noble2026-05-21ubuntu
ubuntulinux-tools-realtime (5.15.0.1084.88) @ jammy2026-05-21ubuntu
ubuntulinux-tools-gcp-fips (5.4.0.1149.91) @ focal2026-05-21ubuntu
ubuntulinux-tools-gke-5.15 (5.15.0.1081.80) @ jammy2026-05-21ubuntu
ubuntulinux-tools-azure-nvidia-lts-24.04 (6.8.0-1022.23) @ noble2026-05-21ubuntu
ubuntulinux-tools-azure-fips (5.15.0.1089.74) @ jammy2026-05-21ubuntu
ubuntulinux-tools-nvidia-tegra-rt (5.15.0.1037.37) @ jammy2026-05-21ubuntu
ubuntulinux-tools-raspi-6.8 (6.8.0-1035.39) @ noble2026-05-21ubuntu
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2028.29) @ noble2026-05-21ubuntu
ubuntulinux-tools-ibm-lts-24.04 (6.8.0-1033.33) @ noble2026-05-21ubuntu
ubuntulinux-tools-oracle-64k (6.11.0-1016.17) @ oracular2026-05-21ubuntu
ubuntulinux-tools-raspi-nolpae (5.15.0.1078.76) @ jammy2026-05-21ubuntu
ubuntulinux-tools-bluefield (5.4.0.1105.101) @ focal2026-05-21ubuntu
ubuntulinux-tools-aws-fips (5.15.0.1084.80) @ jammy2026-05-21ubuntu
ubuntulinux-virtual-6.8 (6.8.0-78.78) @ noble2026-05-21ubuntu
redhatkernel-0:6.12.0-124.8.1.el10_12025-11-11redhat
redhatkernel-0:5.14.0-611.5.1.el9_72025-11-11redhat
linuxKernel @ 5.4.291—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.

Additional Vendor Advisories

(23)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 8× in last 7d / 44× 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 123 total refreshes for this CVE.

  1. 2026-07-22 14:07 UTCEPSS rescore
  2. 2026-07-22 14:07 UTCEPSS rescore
  3. 2026-07-21 15:24 UTCEPSS rescore
  4. 2026-07-20 17:07 UTCEPSS rescore
  5. 2026-07-19 14:30 UTCEPSS rescore
  6. 2026-07-19 14:30 UTCEPSS rescore
  7. 2026-07-18 10:03 UTCEPSS rescore
  8. 2026-07-16 17:02 UTCEPSS rescore
  9. 2026-07-15 16:57 UTCEPSS rescore
  10. 2026-07-15 16:57 UTCEPSS rescore
  11. 2026-07-15 01:59 UTCEPSS rescore
  12. 2026-07-14 13:19 UTCNVD updateCVSS v3 → 5.5 · severity → MEDIUM
  13. 2026-07-14 13:11 UTCMITRE cvelistV5
  14. 2026-07-13 22:29 UTCEPSS rescore
  15. 2026-07-13 22:29 UTCEPSS rescore
  16. 2026-07-13 06:12 UTCEPSS rescore
  17. 2026-07-13 06:12 UTCEPSS rescore
  18. 2026-07-12 05:46 UTCEPSS rescore
  19. 2026-07-12 05:46 UTCEPSS rescore
  20. 2026-07-11 08:27 UTCEPSS rescore
  21. 2026-07-11 08:26 UTCEPSS rescore
  22. 2026-07-10 17:41 UTCOSV refresh
  23. 2026-07-09 19:09 UTCEPSS rescore
  24. 2026-07-08 15:14 UTCEPSS rescore
  25. 2026-07-07 13:45 UTCEPSS rescore
Show 75 more
  1. 2026-07-06 16:26 UTCEPSS rescore
  2. 2026-07-05 02:30 UTCEPSS rescore
  3. 2026-07-04 06:30 UTCEPSS rescore
  4. 2026-07-01 15:06 UTCEPSS rescore
  5. 2026-06-30 23:21 UTCEPSS rescore
  6. 2026-06-30 23:21 UTCEPSS rescore
  7. 2026-06-29 14:06 UTCEPSS rescore
  8. 2026-06-28 14:07 UTCEPSS rescore
  9. 2026-06-28 14:07 UTCEPSS rescore
  10. 2026-06-28 04:55 UTCEPSS rescore
  11. 2026-06-28 04:55 UTCEPSS rescore
  12. 2026-06-27 03:08 UTCEPSS rescore
  13. 2026-06-27 03:08 UTCEPSS rescore
  14. 2026-06-25 13:49 UTCEPSS rescore
  15. 2026-06-25 13:49 UTCEPSS rescore
  16. 2026-06-24 14:04 UTCEPSS rescore
  17. 2026-06-24 14:04 UTCEPSS rescore
  18. 2026-06-23 21:32 UTCEPSS rescore
  19. 2026-06-23 21:32 UTCEPSS rescore
  20. 2026-06-22 14:25 UTCEPSS rescore
  21. 2026-06-22 14:25 UTCEPSS rescore
  22. 2026-06-22 02:07 UTCOSV refresh
  23. 2026-06-21 14:56 UTCEPSS rescore
  24. 2026-06-21 14:56 UTCEPSS rescore
  25. 2026-06-21 01:59 UTCEPSS rescore
  26. 2026-06-21 01:59 UTCEPSS rescore
  27. 2026-06-19 19:25 UTCEPSS rescore
  28. 2026-06-19 19:25 UTCEPSS rescore
  29. 2026-06-18 17:52 UTCEPSS rescore
  30. 2026-06-18 17:52 UTCEPSS rescore
  31. 2026-06-17 17:52 UTCEPSS rescore
  32. 2026-06-16 17:52 UTCEPSS rescore
  33. 2026-06-16 17:52 UTCEPSS rescore
  34. 2026-06-15 17:48 UTCEPSS rescore
  35. 2026-06-14 23:17 UTCEPSS rescore
  36. 2026-06-13 22:59 UTCEPSS rescore
  37. 2026-06-12 23:11 UTCEPSS rescore
  38. 2026-06-11 13:59 UTCEPSS rescore
  39. 2026-06-10 22:18 UTCEPSS rescore
  40. 2026-06-10 13:22 UTCEPSS rescore
  41. 2026-06-08 14:16 UTCEPSS rescore
  42. 2026-06-08 14:16 UTCEPSS rescore
  43. 2026-06-07 15:24 UTCEPSS rescore
  44. 2026-06-07 15:24 UTCEPSS rescore
  45. 2026-06-06 13:47 UTCEPSS rescore
  46. 2026-06-06 13:47 UTCEPSS rescore
  47. 2026-06-05 22:46 UTCEPSS rescore
  48. 2026-06-05 22:46 UTCEPSS rescore
  49. 2026-06-05 06:10 UTCEPSS rescore
  50. 2026-06-05 06:10 UTCEPSS rescore
  51. 2026-06-04 13:11 UTCEPSS rescore
  52. 2026-06-04 13:11 UTCEPSS rescore
  53. 2026-06-03 18:09 UTCOSV refresh
  54. 2026-06-02 20:12 UTCEPSS rescore
  55. 2026-06-02 20:12 UTCEPSS rescore
  56. 2026-06-01 13:51 UTCEPSS rescore
  57. 2026-06-01 13:51 UTCEPSS rescore
  58. 2026-05-31 22:30 UTCEPSS rescore
  59. 2026-05-31 22:30 UTCEPSS rescore
  60. 2026-05-31 00:16 UTCEPSS rescore
  61. 2026-05-31 00:16 UTCEPSS rescore
  62. 2026-05-29 13:44 UTCEPSS rescore
  63. 2026-05-28 13:44 UTCEPSS rescore
  64. 2026-05-28 13:44 UTCEPSS rescore
  65. 2026-05-28 13:44 UTCEPSS rescore
  66. 2026-05-28 13:44 UTCEPSS rescore
  67. 2026-05-27 13:40 UTCEPSS rescore
  68. 2026-05-27 13:40 UTCEPSS rescore
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  72. 2026-05-26 13:43 UTCEPSS rescore
  73. 2026-05-26 13:43 UTCEPSS rescore
  74. 2026-05-26 13:43 UTCEPSS rescore
  75. 2026-05-26 13:43 UTCEPSS rescore

Related CVEs(same product + same vendor)

Frequently asked(5)

What is CVE-2025-21765?
CVE-2025-21765 is a medium vulnerability published on February 27, 2025. In the Linux kernel, the following vulnerability has been resolved: ipv6: use RCU protection in ip6defaultadvmss() ip6defaultadvmss() needs rcu protection to make sure the net structure it reads does not disappear.
When was CVE-2025-21765 disclosed?
CVE-2025-21765 was first published in the National Vulnerability Database on February 27, 2025, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-21765 actively exploited?
CVE-2025-21765 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 12.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2025-21765?
CVE-2025-21765 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2025-21765?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-21765, 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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