CVE-2026-55738

Stack Buffer Overflow in rxi/microtar raw_to_header() via non-null-terminated TAR name field

Published Jun 17, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

Description

A stack-based buffer overflow exists in the raw_to_header function in src/microtar.c in rxi microtar 0.1.0. The function copies the 100-byte name and linkname fields of a TAR header with strcpy without guaranteeing null termination of the source.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

rxi

microtar

affected

Version	Status	Constraints
`0.1.0`	affected	—

No data.

Vendor Product Versions

Rxi

Microtar

Version	Status	Scheme	Platform
`0.1.0`	affected	semver	—

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

No advisories available

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction Passive

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.398% probability within 30 days)

Exploitation none

Automatable no

Technical Impact total

References

Link	Providers
https://github.com/rxi/microtar
https://github.com/rxi/microtar/blob/master/src/microtar.c#L111
https://raw.githubusercontent.com/rxi/microtar/master/src/microtar.c

History

Aug 10, 2026 12:00 PM Description updated. Title updated View changes

Type	Values Removed	Values Added
Description	A stack-based buffer overflow exists in the raw_to_header() function in src/microtar.c in rxi microtar 0.1.0. The function copies the 100-byte name and linkname fields of a TAR header with strcpy() without guaranteeing null termination of the source. The POSIX ustar format permits these fixed-width fields to be fully populated with non-null bytes, so a crafted archive whose linkname field (followed by the trailing padding of the 512-byte raw header) contains no null terminator causes strcpy() to read past the end of the 512-byte raw header stack buffer and to write past the destination header buffer. A remote attacker who supplies a crafted TAR archive that the victim opens or parses (via mtar_open(), mtar_read_header(), or mtar_find()) can cause an out-of-bounds read and a stack buffer overflow, resulting in denial of service (crash) and potentially arbitrary code execution. Confirmed with AddressSanitizer: stack-buffer-overflow READ of size 356 in raw_to_header at src/microtar.c:112.	A stack-based buffer overflow exists in the raw_to_header function in src/microtar.c in rxi microtar 0.1.0. The function copies the 100-byte name and linkname fields of a TAR header with strcpy without guaranteeing null termination of the source.
Title	rxi microtar - Stack Buffer Overflow in raw_to_header() via Non-Null-Terminated TAR Name Field	Stack Buffer Overflow in rxi/microtar raw_to_header() via non-null-terminated TAR name field

Aug 10, 2026 11:45 AM Title updated View changes

Type	Values Removed	Values Added
Title	Stack Buffer Overflow in rxi/microtar raw_to_header() via non-null-terminated TAR name field	rxi microtar - Stack Buffer Overflow in raw_to_header() via Non-Null-Terminated TAR Name Field

Jun 18, 2026 4:45 AM First appearance in the feed. Affected vendors updated. Scoring metrics updated View changes

Type	Values Removed	Values Added
First Time appeared		Rxi Rxi microtar
Vendors & Products		Rxi Rxi microtar
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}`

Jun 17, 2026 2:00 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		A stack-based buffer overflow exists in the raw_to_header() function in src/microtar.c in rxi microtar 0.1.0. The function copies the 100-byte name and linkname fields of a TAR header with strcpy() without guaranteeing null termination of the source. The POSIX ustar format permits these fixed-width fields to be fully populated with non-null bytes, so a crafted archive whose linkname field (followed by the trailing padding of the 512-byte raw header) contains no null terminator causes strcpy() to read past the end of the 512-byte raw header stack buffer and to write past the destination header buffer. A remote attacker who supplies a crafted TAR archive that the victim opens or parses (via mtar_open(), mtar_read_header(), or mtar_find()) can cause an out-of-bounds read and a stack buffer overflow, resulting in denial of service (crash) and potentially arbitrary code execution. Confirmed with AddressSanitizer: stack-buffer-overflow READ of size 356 in raw_to_header at src/microtar.c:112.
Title		Stack Buffer Overflow in rxi/microtar raw_to_header() via non-null-terminated TAR name field
Weaknesses		CWE-121 CWE-170
References		https://github.com/rxi/microtar https://github.com/rxi/microtar/blob/master/src/microtar.c#L111 https://raw.githubusercontent.com/rxi/microtar/master/src/microtar.c
Metrics		cvssV3_1 `{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}` cvssV4_0 `{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}`