CVE-2026-31422

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2026-04-13. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.5Exploit: 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:

net/sched: cls_flow: fix NULL pointer dereference on shared blocks

flow_change() calls tcf_block_q() and dereferences q->handle to derive a default baseclass. Shared blocks leave block->q NULL, causing a NULL deref when a flow filter without a fully qualified baseclass is created on a shared block.

Check tcf_block_shared() before accessing block->q and return -EINVAL for shared blocks. This avoids the null-deref shown below:

======================================================================= KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:flow_change (net/sched/cls_flow.c:508) Call Trace: tc_new_tfilter (net/sched/cls_api.c:2432) rtnetlink_rcv_msg (net/core/rtnetlink.c:6980) [...] =======================================================================

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%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
2%
KEV
Not listed

Published

April 13, 2026

Last Modified

July 14, 2026

Advisory Details (10)

Auto-updated Jul 19, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic🔴 Active Exploitation

SSA-082556

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

SSA-019113

https://cert-portal.siemens.com/productcert/html/ssa-019113.html
generic

net/sched: cls_flow: fix NULL pointer dereference on shared blocks - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/cc707a4fd4c3b6ab2722e06bc359aa010e13d408
generic

net/sched: cls_flow: fix NULL pointer dereference on shared blocks - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a208c3e1232997e9317887294c20008dfcb75449
generic

net/sched: cls_flow: fix NULL pointer dereference on shared blocks - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9bf5fc36a43f7b8b5507c96e74fb81f1e8b4957e
generic

net/sched: cls_flow: fix NULL pointer dereference on shared blocks - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/942813276edeb1741fa5b0a73471beb4e495fa08
generic

net/sched: cls_flow: fix NULL pointer dereference on shared blocks - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/57f94ac7e953eece5ed4819605a18f3cdfc63dcc
generic

net/sched: cls_flow: fix NULL pointer dereference on shared blocks - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4a09f72007201c9f667dc47f64517ec23eea65e5
generic

net/sched: cls_flow: fix NULL pointer dereference on shared blocks - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/415ea0c973c754b9f375225807810eb9045f4293
generic

net/sched: cls_flow: fix NULL pointer dereference on shared blocks - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1a280dd4bd1d616a01d6ffe0de284c907b555504

Vendor Advisories for CVE-2026-31422(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 @ 5.10.253—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 5× in last 7d / 40× 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 132 total refreshes for this CVE.

  1. 2026-07-30 16:27 UTCEPSS rescore
  2. 2026-07-30 01:30 UTCEPSS rescore
  3. 2026-07-28 15:36 UTCEPSS rescore
  4. 2026-07-25 14:18 UTCEPSS rescore
  5. 2026-07-25 14:17 UTCEPSS rescore
  6. 2026-07-24 14:17 UTCEPSS rescore
  7. 2026-07-23 14:18 UTCEPSS rescore
  8. 2026-07-23 14:18 UTCEPSS rescore
  9. 2026-07-23 03:08 UTCEG score recompute
  10. 2026-07-22 14:08 UTCEPSS rescore
  11. 2026-07-22 14:08 UTCEPSS rescore
  12. 2026-07-21 15:24 UTCEPSS rescore
  13. 2026-07-21 15:24 UTCEPSS rescore
  14. 2026-07-20 17:08 UTCEPSS rescore
  15. 2026-07-20 17:08 UTCEPSS rescore
  16. 2026-07-20 11:34 UTCOSV refresh
  17. 2026-07-19 14:31 UTCEPSS rescore
  18. 2026-07-19 14:31 UTCEPSS rescore
  19. 2026-07-18 10:04 UTCEPSS rescore
  20. 2026-07-18 10:04 UTCEPSS rescore
  21. 2026-07-16 17:03 UTCEPSS rescore
  22. 2026-07-16 17:03 UTCEPSS rescore
  23. 2026-07-15 16:57 UTCEPSS rescore
  24. 2026-07-15 16:57 UTCEPSS rescore
  25. 2026-07-15 02:00 UTCEPSS rescore
Show 75 more
  1. 2026-07-15 02:00 UTCEPSS rescore
  2. 2026-07-14 13:19 UTCNVD updateCVSS v3 → 5.5 · severity → MEDIUM
  3. 2026-07-14 13:11 UTCMITRE cvelistV5
  4. 2026-07-13 22:30 UTCEPSS rescore
  5. 2026-07-13 06:13 UTCEPSS rescore
  6. 2026-07-13 06:13 UTCEPSS rescore
  7. 2026-07-11 08:27 UTCEPSS rescore
  8. 2026-07-09 19:10 UTCEPSS rescore
  9. 2026-07-08 15:15 UTCEPSS rescore
  10. 2026-07-07 13:46 UTCEPSS rescore
  11. 2026-07-06 16:27 UTCEPSS rescore
  12. 2026-07-06 16:27 UTCEPSS rescore
  13. 2026-07-06 02:23 UTCEPSS rescore
  14. 2026-07-06 02:23 UTCEPSS rescore
  15. 2026-07-04 06:31 UTCEPSS rescore
  16. 2026-07-01 15:06 UTCEPSS rescore
  17. 2026-06-30 23:22 UTCEPSS rescore
  18. 2026-06-29 14:06 UTCEPSS rescore
  19. 2026-06-29 14:06 UTCEPSS rescore
  20. 2026-06-28 14:07 UTCEPSS rescore
  21. 2026-06-28 14:07 UTCEPSS rescore
  22. 2026-06-27 03:08 UTCEPSS rescore
  23. 2026-06-25 13:49 UTCEPSS rescore
  24. 2026-06-25 13:49 UTCEPSS rescore
  25. 2026-06-24 14:05 UTCEPSS rescore
  26. 2026-06-22 14:25 UTCEPSS rescore
  27. 2026-06-22 14:25 UTCEPSS rescore
  28. 2026-06-21 14:56 UTCEPSS rescore
  29. 2026-06-21 14:56 UTCEPSS rescore
  30. 2026-06-21 01:59 UTCEPSS rescore
  31. 2026-06-19 19:25 UTCEPSS rescore
  32. 2026-06-19 19:25 UTCEPSS rescore
  33. 2026-06-18 17:52 UTCEPSS rescore
  34. 2026-06-18 17:52 UTCEPSS rescore
  35. 2026-06-17 17:53 UTCEPSS rescore
  36. 2026-06-16 17:52 UTCEPSS rescore
  37. 2026-06-15 17:49 UTCEPSS rescore
  38. 2026-06-14 23:18 UTCEPSS rescore
  39. 2026-06-14 21:54 UTCVendor advisory
  40. 2026-06-14 21:54 UTCGHSA enrichment
  41. 2026-06-13 23:00 UTCEPSS rescore
  42. 2026-06-12 23:12 UTCEPSS rescore
  43. 2026-06-12 23:12 UTCEPSS rescore
  44. 2026-06-11 19:38 UTCGHSA enrichment
  45. 2026-06-11 14:00 UTCEPSS rescore
  46. 2026-06-10 22:18 UTCEPSS rescore
  47. 2026-06-10 09:18 UTCVendor advisory
  48. 2026-06-10 09:18 UTCGHSA enrichment
  49. 2026-06-09 11:17 UTCVendor advisory
  50. 2026-06-09 11:17 UTCGHSA enrichment
  51. 2026-06-08 14:17 UTCEPSS rescore
  52. 2026-06-08 14:17 UTCEPSS rescore
  53. 2026-06-08 05:25 UTCVendor advisory
  54. 2026-06-08 05:25 UTCGHSA enrichment
  55. 2026-06-07 15:25 UTCEPSS rescore
  56. 2026-06-07 15:25 UTCEPSS rescore
  57. 2026-06-07 15:25 UTCEPSS rescore
  58. 2026-06-07 07:24 UTCVendor advisory
  59. 2026-06-07 07:24 UTCGHSA enrichment
  60. 2026-06-06 13:47 UTCEPSS rescore
  61. 2026-06-06 13:47 UTCEPSS rescore
  62. 2026-06-05 22:47 UTCEPSS rescore
  63. 2026-06-05 22:47 UTCEPSS rescore
  64. 2026-06-05 06:10 UTCEPSS rescore
  65. 2026-06-05 06:10 UTCEPSS rescore
  66. 2026-06-04 13:12 UTCEPSS rescore
  67. 2026-06-04 13:12 UTCEPSS rescore
  68. 2026-06-02 20:15 UTCVendor advisory
  69. 2026-06-02 20:15 UTCGHSA enrichment
  70. 2026-06-02 20:15 UTCGHSA enrichment
  71. 2026-06-02 20:13 UTCEPSS rescore
  72. 2026-06-02 20:13 UTCEPSS rescore
  73. 2026-06-01 22:13 UTCEG score recompute▲ 5.50
  74. 2026-06-01 22:13 UTCVendor advisory
  75. 2026-06-01 22:13 UTCGHSA enrichment

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

Frequently asked(5)

What is CVE-2026-31422?
CVE-2026-31422 is a medium vulnerability published on April 13, 2026. In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_flow: fix NULL pointer dereference on shared blocks flowchange() calls tcfblock_q() and dereferences q->handle to derive a default baseclass. Shared blocks leave block->q NULL, causing a NULL deref when a flow filter…
When was CVE-2026-31422 disclosed?
CVE-2026-31422 was first published in the National Vulnerability Database on April 13, 2026, 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-2026-31422 actively exploited?
CVE-2026-31422 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 97.6% of all scored CVEs.
What is the CVSS score of CVE-2026-31422?
CVE-2026-31422 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-31422?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-31422, 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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