CVE-2026-67873

CRITICALPre-NVD 9.89.8
EchelonGraph scoreMEDIUM confidence

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

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-06. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: CISA-ADP (Vulnrichment) CVSS v3.1, EPSS, GitHub Security Advisory
Trending — 3 sources updated this weekElevated

Also known asEUVD-2026-53677 (ENISA EUVD) · GHSA-vgf8-x653-r7r2 (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (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: 0.7%CVSS: 9.8Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

A heap-based buffer overflow exists in lib60870-C 2.4.0 in the server-side FileSegment ASDU encoding path. The issue occurs because FileSegment_encode() validates only the standalone segment length via FileSegment_GetMaxDataSize() and does not verify the residual capacity of the current ASDU frame before encoding object fields and segment data

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
75
EG Risk 75/100

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)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 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.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (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: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.7%
EPSS %ILE
54th
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 (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.7% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). 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, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (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)3 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (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

August 5, 2026

Last Modified

August 31, 2026

Advisory Details (4)

Auto-updated Oct 31, 2026
Patch available. Sources: github_release.
Web page

Heap-Based Buffer Overflow in `FileSegment` ASDU Encoding (`CS101_ASDU_addInformationObject` / `FileSegment_encode`) · Issue #201 · mz-automation/lib60870 · GitHub

https://github.com/mz-automation/lib60870/issues/201
GitHub release Patch Available

2.4.0

Patch available: mz-automation/lib60870 v2.4.0

https://github.com/mz-automation/lib60870/releases/tag/v2.4.0
Web page

lib60870/user_guide.adoc at master · mz-automation/lib60870 · GitHub

https://github.com/mz-automation/lib60870/blob/master/user_guide.adoc
Web page

GitHub - mz-automation/lib60870: Official repository for lib60870 an implementation of the IEC 60870-5-101/104 protocol (read-only mirror) · GitHub

https://github.com/mz-automation/lib60870

Vendor Advisories for CVE-2026-67873(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 21× in last 7d / 87× 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 418 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 318 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 18:31 UTCEG score recompute
  2. 2026-11-01 18:31 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  3. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  4. 2026-10-31 19:51 UTCEG score recompute
  5. 2026-10-31 19:51 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  6. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  7. 2026-10-30 21:12 UTCEG score recompute
  8. 2026-10-30 21:12 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  10. 2026-10-29 22:33 UTCEG score recompute
  11. 2026-10-29 22:33 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.7% · 54th percentile
  13. 2026-10-28 23:53 UTCEG score recompute
  14. 2026-10-28 23:53 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  15. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  16. 2026-10-28 01:14 UTCEG score recompute
  17. 2026-10-28 01:14 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  19. 2026-10-27 02:31 UTCEG score recompute
  20. 2026-10-27 02:30 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  22. 2026-10-25 23:47 UTCEG score recompute
  23. 2026-10-25 23:47 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  24. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  25. 2026-10-25 14:10 UTCEG score recompute
Show 75 more
  1. 2026-10-25 01:01 UTCEG score recompute
  2. 2026-10-25 01:01 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  3. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  4. 2026-10-24 02:22 UTCEG score recompute
  5. 2026-10-24 02:22 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  6. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  7. 2026-10-23 03:42 UTCEG score recompute
  8. 2026-10-23 03:42 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  10. 2026-10-22 04:59 UTCEG score recompute
  11. 2026-10-22 04:59 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  13. 2026-10-21 06:17 UTCEG score recompute
  14. 2026-10-21 06:17 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  15. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  16. 2026-10-20 07:38 UTCEG score recompute
  17. 2026-10-20 07:38 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  19. 2026-10-19 08:55 UTCEG score recompute
  20. 2026-10-19 08:55 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-10-18 10:13 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  22. 2026-10-18 03:20 UTCEG score recompute
  23. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  24. 2026-10-17 11:28 UTCEG score recompute
  25. 2026-10-17 11:27 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  26. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  27. 2026-10-16 12:46 UTCEG score recompute
  28. 2026-10-16 12:46 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  29. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  30. 2026-10-15 14:00 UTCEG score recompute
  31. 2026-10-15 14:00 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  32. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  33. 2026-10-14 08:49 UTCEG score recompute
  34. 2026-10-14 08:49 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  35. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  36. 2026-10-13 04:40 UTCEG score recompute
  37. 2026-10-13 04:40 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  38. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  39. 2026-10-12 15:45 UTCEG score recompute
  40. 2026-10-12 05:59 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  41. 2026-10-11 19:30 UTCEG score recompute
  42. 2026-10-11 16:45 UTCEG score recompute
  43. 2026-10-11 14:06 UTCEG score recompute
  44. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  45. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  46. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  47. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  48. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  49. 2026-10-07 04:00 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  50. 2026-10-06 23:40 UTCEG score recompute
  51. 2026-10-06 23:40 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  52. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  53. 2026-10-05 19:40 UTCEG score recompute
  54. 2026-10-05 19:40 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  55. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  56. 2026-10-04 23:38 UTCEG score recompute
  57. 2026-10-04 23:38 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  58. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  59. 2026-10-04 12:25 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  60. 2026-10-04 06:08 UTCEG score recompute
  61. 2026-10-04 06:08 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  62. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  63. 2026-10-03 01:50 UTCEG score recompute
  64. 2026-10-03 01:50 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  65. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  66. 2026-10-02 16:45 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  67. 2026-10-02 10:04 UTCEG score recompute
  68. 2026-10-02 10:04 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  69. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  70. 2026-10-01 15:15 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  71. 2026-10-01 10:57 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  72. 2026-10-01 06:40 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  73. 2026-10-01 02:24 UTCEG score recompute
  74. 2026-10-01 02:24 UTCGHSA enrichmentGHSA-vgf8-x653-r7r2 · GitHub severity CRITICAL · GitHub CVSS 9.8
  75. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 52nd percentile

Frequently asked(5)

What is CVE-2026-67873?
CVE-2026-67873 is a critical-severity vulnerability; its CVE record was published on August 5, 2026. A heap-based buffer overflow exists in lib60870-C 2.4.0 in the server-side FileSegment ASDU encoding path. The issue occurs because FileSegment_encode() validates only the standalone segment length via FileSegment_GetMaxDataSize() and does not verify the residual capacity of the current ASDU frame…
When was the CVE record for CVE-2026-67873 published?
The CVE record for CVE-2026-67873 was published on August 5, 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 31, 2026; the record at its source may have been updated since.
Is CVE-2026-67873 actively exploited?
CVE-2026-67873 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (54th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-67873?
CVE-2026-67873 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-67873?
A fix for CVE-2026-67873 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-67873 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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