CVE-2026-31662

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-04-24. NVD baseline CVSS 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: 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:

tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG

The GRP_ACK_MSG handler in tipc_group_proto_rcv() currently decrements bc_ackers on every inbound group ACK, even when the same member has already acknowledged the current broadcast round.

Because bc_ackers is a u16, a duplicate ACK received after the last legitimate ACK wraps the counter to 65535. Once wrapped, tipc_group_bc_cong() keeps reporting congestion and later group broadcasts on the affected socket stay blocked until the group is recreated.

Fix this by ignoring duplicate or stale ACKs before touching bc_acked or bc_ackers. This makes repeated GRP_ACK_MSG handling idempotent and prevents the underflow path.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
38(Track)
EG Risk 38/100SSVC: 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
Severity75% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
32%
KEV
Not listed

Published

April 24, 2026

Last Modified

August 5, 2026

Advisory Details (8)

Auto-updated Jun 6, 2026
No patch confirmed yet.
generic

tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e0bb732eaf77f9ac2f2638bdac9e39b81e0a9682
generic

tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a7db57ccca21f5801609065473c89a38229ecb92
generic

tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a2ea1ef0167d7a84730638d05c20ccdc421b14b6
generic

tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/575faea557f1a184a5f09661bd47ebd3ef3769f8
generic

tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/48a5fe38772b6f039522469ee6131a67838221a8
generic

tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3bcf7aca63f0bcd679ae28e9b99823c608e59ce3
generic

tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/36ec4fdd6250dcd5e73eb09ea92ed92e9cc28412
generic

tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1b6f13f626665cac67ba5a012765427680518711

Vendor Advisories for CVE-2026-31662(1)

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.

Affected Packages

(5 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (53 versions)5.10.257-1—
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 / 32× 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 262 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 05:46 UTCEG score recompute
  9. 2026-08-16 05:46 UTCVendor advisory
  10. 2026-08-16 05:46 UTCGHSA enrichment
  11. 2026-08-16 02:14 UTCEPSS rescore
  12. 2026-08-15 01:30 UTCEPSS rescore
  13. 2026-08-14 17:02 UTCVendor advisory
  14. 2026-08-14 17:02 UTCGHSA enrichment
  15. 2026-08-14 04:06 UTCEG score recompute
  16. 2026-08-14 04:06 UTCVendor advisory
  17. 2026-08-14 04:06 UTCGHSA enrichment
  18. 2026-08-13 22:00 UTCEPSS rescore
  19. 2026-08-13 08:31 UTCVendor advisory
  20. 2026-08-13 08:31 UTCGHSA enrichment
  21. 2026-08-12 17:48 UTCEG score recompute
  22. 2026-08-12 17:48 UTCVendor advisory
  23. 2026-08-12 17:48 UTCGHSA enrichment
  24. 2026-08-12 13:50 UTCEPSS rescore
  25. 2026-08-11 16:41 UTCEG score recompute
  26. 2026-08-11 16:41 UTCVendor advisory
  27. 2026-08-11 16:41 UTCGHSA enrichment
  28. 2026-08-11 02:08 UTCEG score recompute
  29. 2026-08-11 02:08 UTCVendor advisory
  30. 2026-08-11 02:08 UTCGHSA enrichment
  31. 2026-08-11 00:00 UTCEPSS rescore
  32. 2026-08-10 04:44 UTCVendor advisory
  33. 2026-08-10 04:44 UTCGHSA enrichment
  34. 2026-08-09 16:01 UTCEG score recompute
  35. 2026-08-09 16:01 UTCVendor advisory
  36. 2026-08-09 16:01 UTCGHSA enrichment
  37. 2026-08-09 13:46 UTCEPSS rescore
  38. 2026-08-09 03:18 UTCEG score recompute
  39. 2026-08-09 03:18 UTCVendor advisory
  40. 2026-08-09 03:18 UTCGHSA enrichment
  41. 2026-08-08 16:37 UTCEPSS rescore
  42. 2026-08-08 01:15 UTCEG score recompute
  43. 2026-08-08 01:15 UTCVendor advisory
  44. 2026-08-08 01:15 UTCGHSA enrichment
  45. 2026-08-07 12:32 UTCVendor advisory
  46. 2026-08-07 12:32 UTCGHSA enrichment
  47. 2026-08-06 17:11 UTCEG score recompute
  48. 2026-08-06 17:11 UTCVendor advisory
  49. 2026-08-06 17:11 UTCGHSA enrichment
  50. 2026-08-06 13:46 UTCEPSS rescore
  51. 2026-08-06 01:20 UTCEG score recompute
  52. 2026-08-06 01:20 UTCVendor advisory
  53. 2026-08-06 01:20 UTCGHSA enrichment
  54. 2026-08-05 19:17 UTCEPSS rescore
  55. 2026-08-05 12:37 UTCEG score recompute
  56. 2026-08-05 12:37 UTCVendor advisory
  57. 2026-08-05 12:37 UTCGHSA enrichment
  58. 2026-08-04 15:10 UTCEPSS rescore
  59. 2026-08-04 10:38 UTCEPSS rescore
  60. 2026-08-03 21:00 UTCEG score recompute
  61. 2026-08-03 21:00 UTCVendor advisory
  62. 2026-08-03 21:00 UTCGHSA enrichment
  63. 2026-08-03 10:36 UTCEPSS rescore
  64. 2026-08-02 23:52 UTCVendor advisory
  65. 2026-08-02 23:52 UTCGHSA enrichment
  66. 2026-08-02 11:09 UTCEG score recompute
  67. 2026-08-02 11:09 UTCVendor advisory
  68. 2026-08-02 11:09 UTCGHSA enrichment
  69. 2026-08-02 02:27 UTCEPSS rescore
  70. 2026-08-01 04:16 UTCEPSS rescore
  71. 2026-07-30 16:28 UTCEPSS rescore
  72. 2026-07-30 01:30 UTCEPSS rescore
  73. 2026-07-28 15:36 UTCEPSS rescore
  74. 2026-07-26 14:54 UTCEPSS rescore
  75. 2026-07-26 14:54 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-31662?
CVE-2026-31662 is a high vulnerability published on April 24, 2026. In the Linux kernel, the following vulnerability has been resolved: tipc: fix bcackers underflow on duplicate GRPACK_MSG The GRPACKMSG handler in tipcgroupproto_rcv() currently decrements bc_ackers on every inbound group ACK, even when the same member has already acknowledged the current broadcast…
When was CVE-2026-31662 disclosed?
CVE-2026-31662 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-2026-31662 actively exploited?
CVE-2026-31662 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 67.6% of all scored CVEs.
What is the CVSS score of CVE-2026-31662?
CVE-2026-31662 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-31662?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-31662, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-31662

Explore →

Is Your Infrastructure Affected by CVE-2026-31662?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs