CVE-2026-43623 microtar 0.1.0 Stack-Based Buffer Overflow via raw_to_header()
Attackers can trigger a stack-based buffer overflow in microtar by providing crafted TAR archives, potentially leading to code execution or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-43623?
CVE-2026-43623 is a high-severity memory corruption vulnerability in rxi microtar, published on 1 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-121
Which versions are affected by CVE-2026-43623?
How do I fix CVE-2026-43623?
No fix has been published for CVE-2026-43623 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-43623 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-43623 exists.
Sources
Also known as GHSA-mwwm-v74q-mvh9.