CVE-2026-43623

HIGHPre-NVD 8.88.8
EchelonGraph scoreMEDIUM confidence

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

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-06-01. A secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 3 sources updated this weekElevated

Also known asEUVD-2026-33741 (ENISA EUVD) · GHSA-mwwm-v74q-mvh9 (GitHub Security Advisories)Source: ENISA EUVD

8.8EG
EchelonGraph verdictPlan mitigationRemediate 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: 0.5%CVSS: 8.8Exploit: No code on recordExposed 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 (VulnCheck) lists rxi microtar versions up to and including 0.1.0 as affected. No release containing a fix is confirmed on record.

microtar through 0.1.0 contains a stack-based buffer overflow vulnerability in the raw_to_header() function in src/microtar.c that allows attackers to corrupt adjacent stack memory by supplying a crafted TAR archive with non-null-terminated name or linkname fields. The function uses strcpy() to copy 100-byte ustar format fields that lack null terminators, causing writes of up to 355 bytes into a 100-byte destination buffer when mtar_open(), mtar_find(), or mtar_read_header() process attacker-supplied TAR archives.

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, Track* at medium and Attend at high mission impact.
Exploitation public PoC (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 at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
0.5%
EPSS %ILE
42nd
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.GitHub Security Advisory CVSS
EG Likelihood
0.5% 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, Track* at medium and Attend at high mission impact.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, Track* at medium and Attend at high mission impact.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation public PoC (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

June 1, 2026

Last Modified

July 22, 2026

Advisory Details (4)

Auto-updated Jun 2, 2026
No fix on record yet.
Web page

microtar 0.1.0 Stack-Based Buffer Overflow via raw_to_header() | Advisories | VulnCheck

https://www.vulncheck.com/advisories/microtar-stack-based-buffer-overflow-via-raw-to-header
Web page

Stack Buffer Overflow in raw_to_header() via strcpy on non-null-terminated tar header fields · Issue #30 · rxi/microtar · GitHub

https://github.com/rxi/microtar/issues/30
Web page

[Security] Stack buffer overflow in raw_to_header() via non-null-terminated name field · Issue #29 · rxi/microtar · GitHub

https://github.com/rxi/microtar/issues/29
Web page

Stack buffer overflow in raw_to_header() via strcpy on non-NUL-terminated name/linkname fields · Issue #28 · rxi/microtar · GitHub

https://github.com/rxi/microtar/issues/28

Vendor Advisories for CVE-2026-43623(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 12× in last 7d / 42× 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 284 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 184 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-31 11:15 UTCEG score recompute
  2. 2026-10-31 11:14 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8
  3. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  4. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  5. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  6. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  7. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  8. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  9. 2026-10-25 14:28 UTCEG score recompute
  10. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  11. 2026-10-24 12:44 UTCEG score recompute
  12. 2026-10-24 12:44 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8
  13. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  14. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  15. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  16. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  17. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  18. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  19. 2026-10-18 03:39 UTCEG score recompute
  20. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  21. 2026-10-17 14:11 UTCEG score recompute
  22. 2026-10-17 14:11 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8
  23. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  24. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  25. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.6% · 45th percentile
Show 75 more
  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  3. 2026-10-12 16:06 UTCEG score recompute
  4. 2026-10-11 19:48 UTCEG score recompute
  5. 2026-10-11 17:02 UTCEG score recompute
  6. 2026-10-11 14:28 UTCEG score recompute
  7. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  9. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  10. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  11. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  12. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  13. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  14. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  15. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  16. 2026-10-03 13:39 UTCOSV refresh
  17. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  18. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  19. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  20. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  21. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  22. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  23. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  24. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.3% · 24th 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. 2026-09-14 06:05 UTCEG score recompute
  28. 2026-09-14 06:05 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8
  29. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  30. 2026-09-13 00:06 UTCOSV refresh
  31. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  32. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  33. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  34. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  35. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  36. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  37. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  38. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  39. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  40. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  41. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  42. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  43. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  44. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  45. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  46. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  47. 2026-08-25 03:51 UTCEG score recompute
  48. 2026-08-25 03:51 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8
  49. 2026-08-23 13:49 UTCEG score recompute
  50. 2026-08-23 13:49 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8
  51. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  52. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  53. 2026-08-21 14:49 UTCEG score recompute
  54. 2026-08-21 14:49 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8
  55. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  56. 2026-08-20 21:45 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8
  57. 2026-08-20 10:16 UTCEG score recompute
  58. 2026-08-20 10:16 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8
  59. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  60. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  61. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  62. 2026-08-17 04:42 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8
  63. 2026-08-16 15:00 UTCEG score recompute
  64. 2026-08-16 15:00 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8
  65. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  66. 2026-08-16 02:46 UTCEG score recompute
  67. 2026-08-16 02:46 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8
  68. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  69. 2026-08-15 15:17 UTCEG score recompute
  70. 2026-08-15 15:17 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8
  71. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  72. 2026-08-14 22:18 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8
  73. 2026-08-14 10:49 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8
  74. 2026-08-13 23:20 UTCEG score recompute
  75. 2026-08-13 23:20 UTCGHSA enrichmentGHSA-mwwm-v74q-mvh9 · GitHub severity HIGH · GitHub CVSS 8.8

Frequently asked(5)

What is CVE-2026-43623?
CVE-2026-43623 is a high-severity vulnerability; its CVE record was published on June 1, 2026. microtar through 0.1.0 contains a stack-based buffer overflow vulnerability in the rawtoheader() function in src/microtar.c that allows attackers to corrupt adjacent stack memory by supplying a crafted TAR archive with non-null-terminated name or linkname fields. The function uses strcpy() to copy…
When was CVE-2026-43623 made public?
CVE-2026-43623 was made public on February 16, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on June 1, 2026. EchelonGraph's copy of the record carries a last-modified date of July 22, 2026; the record at its source may have been updated since.
Is CVE-2026-43623 actively exploited?
CVE-2026-43623 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (42nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-43623?
CVE-2026-43623 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-43623?
No fix for CVE-2026-43623 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 (VulnCheck) lists rxi microtar versions up to and including 0.1.0 as affected. No release containing a fix is confirmed on record. The vendor advisories EchelonGraph has for CVE-2026-43623 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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