microtar 0.1.0 Stack-Based Buffer Overflow via raw_to_header()
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2026-43623
- 2026-10-03 Alias added: GHSA-mwwm-v74q-mvh9
References
More rxi vulnerabilities
- TI-2026-03475 rxi fe fe.c read_ out-of-bounds CVSS 4.0MEDIUM 4.8
- TI-2026-49935 microtar Stack Buffer Overflow in mtar_write_file_header() and mtar_write_dir_header() CVSS 3.1CRITICAL 9.8
- TI-2026-40236 Stack Buffer Overflow in rxi/microtar raw_to_header() via non-null-terminated TAR name field CVSS 4.0HIGH 8.7
- TI-2026-39293 Integer Overflow in rxi/microtar mtar_next() Causes Infinite Loop DoS CVSS 4.0HIGH 8.7
Sources
- CVE-2026-43623 · CVE Program
- CVE-2026-43623 · NVD
- FIRST EPSS
- GHSA-mwwm-v74q-mvh9 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-43623 · Red Hat security data · CC BY 4.0
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