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

August 5, 2026

Advisory Details (8)

Auto-updated Sep 9, 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/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/1f2dc36c297d27733f1b380ea644cf15a361bd7b
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/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/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/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/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

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.

Affected Packages

(5 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (54 versions)5.10.259-1—
linux-6.16.1.106-3~deb11u1 ... 6.1.164-1~deb11u1 (16 versions)6.1.170-1~deb11u1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (48 versions)6.1.170-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.85-1~bpo12+1 (17 versions)6.12.85-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 6.19~rc8-1~exp1 (127 versions)6.19.13-1—

Weakness Classification(1)

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

Additional Vendor Advisories

(24)

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 5× in last 7d / 34× 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 410 total refreshes for this CVE.

  1. 2026-09-13 16:47 UTCEPSS rescore
  2. 2026-09-12 15:01 UTCEPSS rescore
  3. 2026-09-11 14:52 UTCEPSS rescore
  4. 2026-09-10 09:34 UTCEPSS rescore
  5. 2026-09-08 22:00 UTCEPSS rescore
  6. 2026-09-07 16:01 UTCEPSS rescore
  7. 2026-09-06 13:47 UTCEPSS rescore
  8. 2026-09-06 13:47 UTCEPSS rescore
  9. 2026-09-04 05:06 UTCEPSS rescore
  10. 2026-09-04 03:16 UTCOSV refresh
  11. 2026-09-02 14:11 UTCEPSS rescore
  12. 2026-09-01 13:53 UTCEPSS rescore
  13. 2026-09-01 04:39 UTCEPSS rescore
  14. 2026-09-01 04:39 UTCEPSS rescore
  15. 2026-08-30 19:17 UTCEPSS rescore
  16. 2026-08-30 01:22 UTCEPSS rescore
  17. 2026-08-28 21:41 UTCEPSS rescore
  18. 2026-08-27 14:25 UTCEPSS rescore
  19. 2026-08-26 14:46 UTCEPSS rescore
  20. 2026-08-25 13:49 UTCEPSS rescore
  21. 2026-08-24 14:17 UTCEPSS rescore
  22. 2026-08-23 00:19 UTCEPSS rescore
  23. 2026-08-21 23:49 UTCEPSS rescore
  24. 2026-08-20 22:55 UTCEPSS rescore
  25. 2026-08-20 22:55 UTCEPSS rescore
Show 75 more
  1. 2026-08-19 17:03 UTCEPSS rescore
  2. 2026-08-18 13:48 UTCEPSS rescore
  3. 2026-08-17 14:48 UTCEG score recompute
  4. 2026-08-17 14:48 UTCVendor advisory
  5. 2026-08-17 14:48 UTCGHSA enrichment
  6. 2026-08-17 13:47 UTCEPSS rescore
  7. 2026-08-16 14:56 UTCEPSS rescore
  8. 2026-08-16 09:51 UTCVendor advisory
  9. 2026-08-16 09:50 UTCGHSA enrichment
  10. 2026-08-16 05:46 UTCEG score recompute
  11. 2026-08-16 05:46 UTCVendor advisory
  12. 2026-08-16 05:46 UTCGHSA enrichment
  13. 2026-08-16 02:14 UTCEPSS rescore
  14. 2026-08-15 01:30 UTCEPSS rescore
  15. 2026-08-15 00:26 UTCVendor advisory
  16. 2026-08-15 00:26 UTCGHSA enrichment
  17. 2026-08-14 20:22 UTCVendor advisory
  18. 2026-08-14 20:22 UTCGHSA enrichment
  19. 2026-08-14 16:18 UTCVendor advisory
  20. 2026-08-14 16:18 UTCGHSA enrichment
  21. 2026-08-14 12:14 UTCVendor advisory
  22. 2026-08-14 12:14 UTCGHSA enrichment
  23. 2026-08-14 08:10 UTCVendor advisory
  24. 2026-08-14 08:10 UTCGHSA enrichment
  25. 2026-08-14 04:06 UTCEG score recompute
  26. 2026-08-14 04:06 UTCVendor advisory
  27. 2026-08-14 04:06 UTCGHSA enrichment
  28. 2026-08-13 22:00 UTCEPSS rescore
  29. 2026-08-13 08:31 UTCVendor advisory
  30. 2026-08-13 08:31 UTCGHSA enrichment
  31. 2026-08-13 01:56 UTCVendor advisory
  32. 2026-08-13 01:56 UTCGHSA enrichment
  33. 2026-08-12 21:52 UTCVendor advisory
  34. 2026-08-12 21:52 UTCGHSA enrichment
  35. 2026-08-12 17:48 UTCEG score recompute
  36. 2026-08-12 17:48 UTCVendor advisory
  37. 2026-08-12 17:48 UTCGHSA enrichment
  38. 2026-08-12 13:50 UTCEPSS rescore
  39. 2026-08-12 00:49 UTCVendor advisory
  40. 2026-08-12 00:48 UTCGHSA enrichment
  41. 2026-08-11 20:45 UTCVendor advisory
  42. 2026-08-11 20:44 UTCGHSA enrichment
  43. 2026-08-11 16:41 UTCEG score recompute
  44. 2026-08-11 16:41 UTCVendor advisory
  45. 2026-08-11 16:41 UTCGHSA enrichment
  46. 2026-08-11 06:12 UTCVendor advisory
  47. 2026-08-11 06:12 UTCGHSA enrichment
  48. 2026-08-11 02:09 UTCEG score recompute
  49. 2026-08-11 02:09 UTCVendor advisory
  50. 2026-08-11 02:09 UTCGHSA enrichment
  51. 2026-08-11 00:00 UTCEPSS rescore
  52. 2026-08-10 13:03 UTCVendor advisory
  53. 2026-08-10 13:03 UTCGHSA enrichment
  54. 2026-08-10 08:59 UTCVendor advisory
  55. 2026-08-10 08:59 UTCGHSA enrichment
  56. 2026-08-10 04:54 UTCVendor advisory
  57. 2026-08-10 04:54 UTCGHSA enrichment
  58. 2026-08-10 00:50 UTCVendor advisory
  59. 2026-08-10 00:50 UTCGHSA enrichment
  60. 2026-08-09 20:46 UTCVendor advisory
  61. 2026-08-09 20:46 UTCGHSA enrichment
  62. 2026-08-09 16:43 UTCEG score recompute
  63. 2026-08-09 16:43 UTCVendor advisory
  64. 2026-08-09 16:43 UTCGHSA enrichment
  65. 2026-08-09 13:46 UTCEPSS rescore
  66. 2026-08-09 12:38 UTCVendor advisory
  67. 2026-08-09 12:38 UTCGHSA enrichment
  68. 2026-08-09 07:22 UTCVendor advisory
  69. 2026-08-09 07:22 UTCGHSA enrichment
  70. 2026-08-09 03:18 UTCEG score recompute
  71. 2026-08-09 03:18 UTCVendor advisory
  72. 2026-08-09 03:18 UTCGHSA enrichment
  73. 2026-08-08 16:37 UTCEPSS rescore
  74. 2026-08-08 12:59 UTCVendor advisory
  75. 2026-08-08 12:59 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 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-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 66.5% 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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