CVE-2026-5066

HIGHNVD 8.88.8
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 8.8 under NVD CVSS v3. EPSS exploit probability: 0.3% (24th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
Elevated

Also known asEUVD-2026-34324 (ENISA EUVD)Source: ENISA EUVD

8.8EG
EchelonGraph verdictPlan mitigationRemediate within your standard update timelines (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 8.8Exploit: No code on recordExposed services: Not assessed

A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).

A potential out-of-bounds write/read exists in the TLS socket connect path of the network sockets subsystem (subsys/net/lib/sockets/sockets_tls.c). When the TLS session cache is enabled, tls_session_store() and tls_session_restore() memcpy the caller-supplied address into a fixed-size buffer using the caller-controlled addrlen value without validating it against the destination size. struct net_sockaddr is an opaque type, so an application can pass an addrlen larger than sizeof(struct net_sockaddr) (for example 128 bytes into a 24-byte stack buffer), causing the memcpy to read and write past the end of the address memory used by the TLS session cache. This out-of-bounds write can lead to a crash and denial of service, and potentially to arbitrary code execution.

CVSS v3
8.8
EG Score
8.8HIGHmedium confidence
EG Risk
56
EG Risk 56/100

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)
Severity88% × 45%
Impact severity (EG Severity): CVSS 8.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
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 public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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: A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines; until then, restrict network exposure of the affected system or apply the vendor's mitigation.
EPSS PROB
0.3%
EPSS %ILE
24th
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 (8.8): severity, escalated by confirmed exploitation. This CVE's 8.8 is its impact severity (EG Severity), not escalated.

EG Severity
8.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-30). 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: 60 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).

A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines; until then, restrict network exposure of the affected system or apply the vendor's mitigation.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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)60 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 partial (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

June 4, 2026

Last Modified

October 15, 2026

Advisory Details (1)

Auto-updated Jun 14, 2026
Fix referenced — no release confirmed yet. Sources: github.
GitHub advisoryMentions a patch (unverified)

net: sockets: tls: Potential out-of-bounds write/read in socket_op_vtable::connect function · Advisory · zephyrproject-rtos/zephyr · GitHub

https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wgrc-jrf6-24f3

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 40× 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 194 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 94 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-31 04:04 UTCEG score recompute
  2. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  3. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  4. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  5. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  6. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  7. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  8. 2026-10-25 14:21 UTCEG score recompute
  9. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  10. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  11. 2026-10-23 13:50 UTCEG score recompute
  12. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  13. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  14. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  15. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  16. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  17. 2026-10-18 03:33 UTCEG score recompute
  18. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  19. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  20. 2026-10-15 22:30 UTCEG score recompute
  21. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  22. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  23. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  24. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  25. 2026-10-12 15:59 UTCEG score recompute
Show 75 more
  1. 2026-10-11 19:42 UTCEG score recompute
  2. 2026-10-11 16:57 UTCEG score recompute
  3. 2026-10-11 14:20 UTCEG score recompute
  4. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  5. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  6. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  7. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  8. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  9. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  10. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  11. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  12. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  13. 2026-10-03 12:09 UTCOSV refresh
  14. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  15. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  16. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  17. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  18. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  19. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  20. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  21. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  22. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  23. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  24. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  25. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  26. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  27. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  28. 2026-09-14 05:20 UTCEG score recompute
  29. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  30. 2026-09-12 23:36 UTCOSV refresh
  31. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  32. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  33. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  34. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  35. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  36. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  37. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  38. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  39. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  40. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  41. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  42. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  43. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  44. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  45. 2026-08-25 03:27 UTCEG score recompute
  46. 2026-08-23 12:41 UTCEG score recompute
  47. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  48. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  49. 2026-08-21 14:35 UTCEG score recompute
  50. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  51. 2026-08-20 09:55 UTCEG score recompute
  52. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  53. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  54. 2026-08-17 15:42 UTCEG score recompute
  55. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  56. 2026-08-17 03:20 UTCEG score recompute
  57. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  58. 2026-08-16 02:17 UTCEG score recompute
  59. 2026-08-15 14:20 UTCEG score recompute
  60. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  61. 2026-08-13 22:38 UTCEG score recompute
  62. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  63. 2026-08-12 22:14 UTCEG score recompute
  64. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  65. 2026-08-11 22:14 UTCEG score recompute
  66. 2026-08-11 10:11 UTCEG score recompute
  67. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  68. 2026-08-09 20:11 UTCEG score recompute
  69. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  70. 2026-08-08 20:16 UTCEG score recompute
  71. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  72. 2026-08-07 20:21 UTCEG score recompute
  73. 2026-08-06 20:24 UTCEG score recompute
  74. 2026-08-06 13:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  75. 2026-08-05 20:28 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-5066?
CVE-2026-5066 is a high-severity vulnerability; its CVE record was published on June 4, 2026. A potential out-of-bounds write/read exists in the TLS socket connect path of the network sockets subsystem (subsys/net/lib/sockets/socketstls.c). When the TLS session cache is enabled, tlssessionstore() and tlssessionrestore() memcpy the caller-supplied address into a fixed-size buffer using the…
When was the CVE record for CVE-2026-5066 published?
The CVE record for CVE-2026-5066 was published on June 4, 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 October 15, 2026; the record at its source may have been updated since.
Is CVE-2026-5066 actively exploited?
CVE-2026-5066 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (24th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-5066?
CVE-2026-5066 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-5066?
A fix for CVE-2026-5066 is referenced (a reference tagged "Patch", often a source commit), but EchelonGraph has no release containing it on record. Check that reference and the vendor's advisory for a release that contains the fix and update to it; until then, restrict network exposure of the affected system or apply the vendor's mitigation.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-5066

Explore →

Is Your Infrastructure Affected by CVE-2026-5066?

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

Book a Demo →Browse All CVEs