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
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 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)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity98% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
33%
KEV
Not listed

Published

April 24, 2026

Last Modified

June 1, 2026

Advisory Details (8)

Auto-updated Jul 26, 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.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
linuxKernel @ 5.10.258—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.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× 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 260 total refreshes for this CVE.

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

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

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 0% probability of exploitation in the next 30 days, which ranks it in the top 67.3% of all scored CVEs.
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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