CVE-2026-31657

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-04-24. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.8Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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

batman-adv: hold claim backbone gateways by reference

batadv_bla_add_claim() can replace claim->backbone_gw and drop the old gateway's last reference while readers still follow the pointer.

The netlink claim dump path dereferences claim->backbone_gw->orig and takes claim->backbone_gw->crc_lock without pinning the underlying backbone gateway. batadv_bla_check_claim() still has the same naked pointer access pattern.

Reuse batadv_bla_claim_get_backbone_gw() in both readers so they operate on a stable gateway reference until the read-side work is complete. This keeps the dump and claim-check paths aligned with the lifetime rules introduced for the other BLA claim readers.

CVSS v3
9.8
EG Score
9.8(medium)
EPSS
32.2%
KEV
Not listed

Published

April 24, 2026

Last Modified

June 1, 2026

Advisory Details (8)

Auto-updated Jun 20, 2026
No patch confirmed yet.
generic

batman-adv: hold claim backbone gateways by reference - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f4858832ddef2f39f21e30b7226bbcd3c4b2bc96
generic

batman-adv: hold claim backbone gateways by reference - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/82d8701b2c930d0e96b0dbc9115a218d791cb0d2
generic

batman-adv: hold claim backbone gateways by reference - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/7962b522222628596ca9ecc8722efc95367aadbd
generic

batman-adv: hold claim backbone gateways by reference - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/69d1ce9c72eca91203ffdb8d08bacd511100aec6
generic

batman-adv: hold claim backbone gateways by reference - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5202f071b367ffbc8e279fc7a00db14f5e587f52
generic

batman-adv: hold claim backbone gateways by reference - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4dee4c0688443aaf5bbec74aa203c851d1d53c35
generic

batman-adv: hold claim backbone gateways by reference - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2f55b58b5a0bbed192d60c444a45a49cdf1b545f
generic

batman-adv: hold claim backbone gateways by reference - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1f2dc36c297d27733f1b380ea644cf15a361bd7b

Vendor Advisories for CVE-2026-31657(2)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 43× 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 237 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-31657?
CVE-2026-31657 is a critical vulnerability published on April 24, 2026. In the Linux kernel, the following vulnerability has been resolved: batman-adv: hold claim backbone gateways by reference batadvblaaddclaim() can replace claim->backbonegw and drop the old gateway's last reference while readers still follow the pointer. The netlink claim dump path dereferences…
When was CVE-2026-31657 disclosed?
CVE-2026-31657 was first published in the National Vulnerability Database on April 24, 2026, with the most recent update on June 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-31657 actively exploited?
CVE-2026-31657 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 32.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-31657?
CVE-2026-31657 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-31657?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-31657, 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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