CVE-2026-45251

HIGHNVD 7.87.8
EchelonGraph scoreMEDIUM confidence

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

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-05-21. NVD baseline CVSS 7.8; 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
7.8EG
EchelonGraph verdictPlan mitigationRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.8Exploit: None knownExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

The CVE record's CNA (FreeBSD) lists FreeBSD versions 15.0-RELEASE up to but not including p9, 14.4-RELEASE up to but not including p5 and 14.3-RELEASE up to but not including p14 as affected. No release containing a fix is confirmed on record.

A file descriptor can be closed while a thread is blocked in a poll(2) or select(2) call waiting for that descriptor. Because the blocked thread does not hold a reference to the underlying object, this closure may result in the object being freed while the thread remains blocked. In this situation, the kernel must remove the blocked thread from the per-object wait queue prior to freeing the object.

In the case of some file descriptor types, the kernel failed to unlink blocked threads from the object before freeing it. When the blocked thread is subsequently woken, it accesses memory that has already been freed resulting in a use-after-free vulnerability.

The use-after-free vulnerability may be triggered by an unprivileged local user and can be exploited to obtain superuser privileges.

CVSS v3
7.8
EG Score
7.8HIGHmedium confidence
EG Risk
35
EG Risk 35/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity78% × 45%
Impact severity (EG Severity): CVSS 7.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.1% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.2%
EPSS %ILE
4th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.

EG Severity
7.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-17). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

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

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (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 Vulnrichment) · Technical impact total (CISA Vulnrichment). 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

May 21, 2026

Last Modified

July 23, 2026

Advisory Details (1)

Auto-updated Jun 4, 2026
No fix on record yet.

Vendor Advisories for CVE-2026-45251(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 31× 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 100 of 246 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. None are among the latest 100 rows. The 146 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  2. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  3. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  4. 2026-10-18 03:38 UTCEG score recompute
  5. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  6. 2026-10-17 13:42 UTCEG score recompute
  7. 2026-10-17 13:42 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  8. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  9. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  10. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  11. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  12. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  13. 2026-10-12 16:04 UTCEG score recompute
  14. 2026-10-11 19:46 UTCEG score recompute
  15. 2026-10-11 17:01 UTCEG score recompute
  16. 2026-10-11 14:26 UTCEG score recompute
  17. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  18. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  19. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  20. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  21. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  22. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  23. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  24. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  25. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
Show 75 more
  1. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  2. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  3. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  4. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  5. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  6. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  7. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  8. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  9. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  10. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  11. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  12. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  13. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  14. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  15. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  16. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  17. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  18. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  19. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  20. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  21. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  22. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  23. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  24. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  25. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  26. 2026-08-23 16:50 UTCEG score recompute
  27. 2026-08-23 16:50 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  28. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  29. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  30. 2026-08-21 21:48 UTCEG score recompute
  31. 2026-08-21 21:47 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  32. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  33. 2026-08-20 18:50 UTCEG score recompute
  34. 2026-08-20 18:50 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  35. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  36. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  37. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  38. 2026-08-17 09:49 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  39. 2026-08-16 16:51 UTCEG score recompute
  40. 2026-08-16 16:51 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  41. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  42. 2026-08-16 03:26 UTCEG score recompute
  43. 2026-08-16 03:26 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  44. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  45. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  46. 2026-08-15 01:07 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  47. 2026-08-14 13:32 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  48. 2026-08-14 01:58 UTCEG score recompute
  49. 2026-08-14 01:58 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  50. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  51. 2026-08-13 01:48 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  52. 2026-08-12 14:14 UTCEG score recompute
  53. 2026-08-12 14:14 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  54. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  55. 2026-08-12 01:24 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  56. 2026-08-11 13:50 UTCEG score recompute
  57. 2026-08-11 13:50 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  58. 2026-08-11 00:32 UTCEG score recompute
  59. 2026-08-11 00:32 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  60. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  61. 2026-08-10 12:12 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  62. 2026-08-10 00:38 UTCEG score recompute
  63. 2026-08-10 00:38 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  64. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  65. 2026-08-09 13:03 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  66. 2026-08-09 01:29 UTCEG score recompute
  67. 2026-08-09 01:29 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  68. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  69. 2026-08-08 07:07 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  70. 2026-08-07 19:33 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  71. 2026-08-07 07:58 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  72. 2026-08-06 20:23 UTCEG score recompute
  73. 2026-08-06 20:23 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8
  74. 2026-08-06 13:47 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  75. 2026-08-06 08:48 UTCGHSA enrichmentGHSA-wp9w-fp98-2cxm · GitHub severity HIGH · GitHub CVSS 7.8

Frequently asked(5)

What is CVE-2026-45251?
CVE-2026-45251 is a high-severity vulnerability; its CVE record was published on May 21, 2026. A file descriptor can be closed while a thread is blocked in a poll(2) or select(2) call waiting for that descriptor. Because the blocked thread does not hold a reference to the underlying object, this closure may result in the object being freed while the thread remains blocked. In this situation,…
When was CVE-2026-45251 made public?
CVE-2026-45251 was made public on May 20, 2026: that is the date its CVE record's CNA, FreeBSD, gives for when the vulnerability was made public. The CVE record itself was published on May 21, 2026. EchelonGraph's copy of the record carries a last-modified date of July 23, 2026; the record at its source may have been updated since.
Is CVE-2026-45251 actively exploited?
CVE-2026-45251 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (4th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-45251?
CVE-2026-45251 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-45251?
No fix for CVE-2026-45251 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The CVE record's CNA (FreeBSD) lists FreeBSD versions 15.0-RELEASE up to but not including p9, 14.4-RELEASE up to but not including p5 and 14.3-RELEASE up to but not including p14 as affected. No release containing a fix is confirmed on record. The vendor advisories EchelonGraph has for CVE-2026-45251 are linked in the Vendor Advisories panel on this page.

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