CVE-2026-43491

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2026-05-19. 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

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: qrtr: ns: Limit the maximum server registration per node

Current code does no bound checking on the number of servers added per node. A malicious client can flood NEW_SERVER messages and exhaust memory.

Fix this issue by limiting the maximum number of server registrations to 256 per node. If the NEW_SERVER message is received for an old port, then don't restrict it as it will get replaced. While at it, also rate limit the error messages in the failure path of qrtr_ns_worker().

Note that the limit of 256 is chosen based on the current platform requirements. If requirement changes in the future, this limit can be increased.

CVSS v3
5.5
EG Score
5.5(medium)
EPSS
4.1%
KEV
Not listed

Published

May 19, 2026

Last Modified

June 26, 2026

Advisory Details (5)

Auto-updated Jun 26, 2026
No patch confirmed yet.
generic

net: qrtr: ns: Limit the maximum server registration per node - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e6f6cd501fb54060940a6eb3f4103eeb5e426ae7
generic

net: qrtr: ns: Limit the maximum server registration per node - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d5ee2ff98322337951c56398e79d51815acbf955
generic

net: qrtr: ns: Limit the maximum server registration per node - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/868202aa2adae427060a42d5bd663b4d782ec02c
generic

net: qrtr: ns: Limit the maximum server registration per node - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3efaad55cad1ded429e3a873bfece389058a526b
generic

net: qrtr: ns: Limit the maximum server registration per node - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/35fb4a0c077c5d1049c2628b769e0a1b1e65df0d

Vendor Advisories for CVE-2026-43491(2)

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

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.

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

Frequently asked(5)

What is CVE-2026-43491?
CVE-2026-43491 is a medium vulnerability published on May 19, 2026. In the Linux kernel, the following vulnerability has been resolved: net: qrtr: ns: Limit the maximum server registration per node Current code does no bound checking on the number of servers added per node. A malicious client can flood NEW_SERVER messages and exhaust memory. Fix this issue by…
When was CVE-2026-43491 disclosed?
CVE-2026-43491 was first published in the National Vulnerability Database on May 19, 2026, with the most recent update on June 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43491 actively exploited?
CVE-2026-43491 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 4.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-43491?
CVE-2026-43491 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-43491?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43491, 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.

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