CVE-2026-43623Public exploitNetwork attack vector

Code execution via unterminated TAR header fields

Published Jun 1, 2026 · Updated Jun 1, 2026

Stack-based buffer overflow in rxi microtar 0.1.0 and earlier allows attackers to corrupt stack memory via a crafted TAR archive. The raw_to_header() function passes fixed-width name and linkname fields to strcpy() without ensuring null termination, so copying continues beyond each 100-byte destination. The victim application must parse the archive; the demonstrated consequence is a crash, while controlled stack corruption enables code execution.

CVSS severity8.7
High
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in rxi microtar 0.1.0 and earlier allows attackers to corrupt stack memory via a crafted TAR archive. The raw_to_header() function passes fixed-width name and linkname fields to strcpy() without ensuring null termination, so copying continues beyond each 100-byte destination. The victim application must parse the archive; the demonstrated consequence is a crash, while controlled stack corruption enables code execution.

The record

CVE
CVE-2026-43623
Published
Jun 1, 2026
Updated
Jun 1, 2026
Vendor
rxi
Product
microtar
Classifications
CWE-121, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=0.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

rxi · microtarversion=0 <=0.1.0

Published CVSS scores

8.7VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
8.8VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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