CVE-2026-23139

MEDIUMNVD 5.55.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

Score 5.5 from GitHub Security Advisory published 2026-02-14. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 3 sources updated this week
5.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 5.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_conncount: update last_gc only when GC has been performed

Currently last_gc is being updated everytime a new connection is tracked, that means that it is updated even if a GC wasn't performed. With a sufficiently high packet rate, it is possible to always bypass the GC, causing the list to grow infinitely.

Update the last_gc value only when a GC has been actually performed.

CVSS v3
5.5
EG Score
5.5MEDIUMmedium confidence
EG Risk
25
EG Risk 25/100

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 (value × EchelonGraph’s weight)
Severity55% × 45%
The EG Score, 5.5 of 10.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
30th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

February 14, 2026

Last Modified

August 5, 2026

Advisory Details (7)

Auto-updated Aug 5, 2026
Patch available.
Web page

netfilter: nf_conncount: update last_gc only when GC has been performed - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/7811ba452402d58628e68faedf38745b3d485e3c
Web page

netfilter: nf_conncount: update last_gc only when GC has been performed - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8bdafdf4900040a81422056cabe5e00a37bd101a
Web page

netfilter: nf_conncount: update last_gc only when GC has been performed - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/26a82dce2beee39c43c109d9647e16f49cb02a35
Web page

netfilter: nf_conncount: update last_gc only when GC has been performed - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3cd717359e56f82f06cbf8279b47a7d79880c6f3
Web page

netfilter: nf_conncount: update last_gc only when GC has been performed - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9f45588993d7f115280fc726119ca86fba32a811
Web page

netfilter: nf_conncount: update last_gc only when GC has been performed - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c4cde57c8affdcca5bcff53a1047e15d268bdca1
Web page

netfilter: nf_conncount: update last_gc only when GC has been performed - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2c7c71113ed6d3e2f3aca4c088f22283016ff34f

Vendor Advisories for CVE-2026-23139(1)

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

Patch Availability(9)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1054.57.1) @ noble2026-06-12ubuntu
ubuntulinux-virtual-6.8 (6.8.0-117.117) @ noble2026-06-12ubuntu
ubuntulinux-tools-fips-6.8 (6.8.0-116.116+fips1) @ noble2026-06-12ubuntu
ubuntulinux-tools-nvidia-tegra-rt-6.8 (6.8.0-1024.24) @ noble2026-06-12ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1059.65+fips1) @ noble2026-06-12ubuntu
ubuntulinux-tools-nvidia-hwe-22.04-edge (6.8.0-1054.57~22.04.1) @ jammy2026-06-12ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1056.62) @ noble2026-06-12ubuntu
redhatkernel-0:6.12.0-55.72.1.el10_02026-05-11redhat
linuxKernel @ 6.1.161 (fixes >=5.19.0)—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

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 6.1.99-1 (46 versions)
  • every version up to 6.1.162-1: fixed in 6.1.162-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.69-1~bpo12+1 (10 versions)
  • every version up to 6.12.69-1: fixed in 6.12.69-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 6.18~rc7-1~exp1 (97 versions)
  • every version up to 6.18.8-1: fixed in 6.18.8-1
—

Additional Vendor Advisories

(14)

Data Freshness Timeline

(refreshed 12× in last 7d / 29× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 96 of 224 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 4 repeat rows among the latest 100 are merged into the row they repeat. The 128 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  2. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  3. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  4. 2026-10-12 16:21 UTCEG score recompute
  5. 2026-10-11 20:03 UTCEG score recompute
  6. 2026-10-11 17:16 UTCEG score recompute
  7. 2026-10-11 14:48 UTCEG score recompute
  8. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  9. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  11. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  12. 2026-10-08 15:35 UTCOSV refresh
  13. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  14. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  15. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  16. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  17. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  18. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  19. 2026-09-29 15:21 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  20. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  21. 2026-09-27 13:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  22. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  23. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  24. 2026-09-24 14:03 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  25. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.3% · 27th percentile
Show 71 more
  1. 2026-09-18 21:36 UTCOSV refresh
  2. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  3. 2026-09-16 14:07 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  4. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  5. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  6. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  7. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  8. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  9. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  10. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  11. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  12. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  13. 2026-09-02 14:11 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  14. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  15. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  16. 2026-08-31 00:23 UTCOSV refresh
  17. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  18. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  19. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  20. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  21. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  22. 2026-08-25 13:48 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  23. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  24. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  25. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  26. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  27. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  28. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  29. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  30. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  31. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  32. 2026-08-14 10:05 UTCEG score recompute
  33. 2026-08-14 10:05 UTCVendor advisory
  34. 2026-08-14 10:05 UTCGHSA enrichmentGHSA-cf2j-m586-269w · GitHub CVSS 5.5
  35. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  36. 2026-08-13 02:23 UTCEG score recompute
  37. 2026-08-13 02:23 UTCVendor advisory
  38. 2026-08-13 02:23 UTCGHSA enrichmentGHSA-cf2j-m586-269w · GitHub CVSS 5.5
  39. 2026-08-12 13:50 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  40. 2026-08-11 13:42 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  41. 2026-08-11 07:55 UTCEG score recompute
  42. 2026-08-11 07:55 UTCVendor advisory
  43. 2026-08-11 07:54 UTCGHSA enrichmentGHSA-cf2j-m586-269w · GitHub CVSS 5.5
  44. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  45. 2026-08-09 14:39 UTCEG score recompute
  46. 2026-08-09 14:39 UTCVendor advisory
  47. 2026-08-09 14:39 UTCGHSA enrichmentGHSA-cf2j-m586-269w · GitHub CVSS 5.5
  48. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  49. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  50. 2026-08-07 21:56 UTCEG score recompute
  51. 2026-08-07 21:56 UTCVendor advisory
  52. 2026-08-07 21:56 UTCGHSA enrichmentGHSA-cf2j-m586-269w · GitHub CVSS 5.5
  53. 2026-08-06 13:46 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  54. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  55. 2026-08-05 12:45 UTCEG score recompute
  56. 2026-08-05 12:45 UTCVendor advisory
  57. 2026-08-05 12:45 UTCGHSA enrichmentGHSA-cf2j-m586-269w · GitHub CVSS 5.5
  58. 2026-08-04 15:10 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  59. 2026-08-04 10:38 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  60. 2026-08-02 20:35 UTCEG score recompute▼ 2.00
  61. 2026-08-02 20:35 UTCVendor advisory
  62. 2026-08-02 20:35 UTCGHSA enrichmentGHSA-cf2j-m586-269w · GitHub CVSS 5.5
  63. 2026-08-02 02:26 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  64. 2026-08-01 04:15 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  65. 2026-07-30 01:30 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  66. 2026-07-27 14:13 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  67. 2026-07-26 14:54 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  68. 2026-07-25 14:17 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  69. 2026-07-24 14:17 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  70. 2026-07-23 14:18 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  71. 2026-07-23 03:06 UTCEG score recompute▲ 2.00

Frequently asked(5)

What is CVE-2026-23139?
CVE-2026-23139 is a medium-severity vulnerability; its CVE record was published on February 14, 2026. In the Linux kernel, the following vulnerability has been resolved: netfilter: nfconncount: update lastgc only when GC has been performed Currently last_gc is being updated everytime a new connection is tracked, that means that it is updated even if a GC wasn't performed. With a sufficiently high…
When was the CVE record for CVE-2026-23139 published?
The CVE record for CVE-2026-23139 was published on February 14, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of August 5, 2026; the record at its source may have been updated since.
Is CVE-2026-23139 actively exploited?
CVE-2026-23139 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (30th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-23139?
CVE-2026-23139 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-23139?
A fix for CVE-2026-23139 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-23139 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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