CVE-2026-68768 hashcat through 7.1.2 Heap Buffer Overflow in outfile_write() via Oversized Username
An attacker can cause a heap buffer overflow in hashcat by providing an oversized username in a crafted hash file, leading to memory corruption or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-68768?
CVE-2026-68768 is a medium-severity memory corruption vulnerability in hashcat, published on 22 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
hashcat contains a heap-based buffer overflow (out-of-bounds write) in the outfile_write() function in src/outfile.c. When assembling output into a fixed-size buffer (HCBUFSIZ_LARGE, ~16 MB), the function sequentially appends the username, separator, hash, and plaintext via memcpy without validating that the accumulated length stays within the buffer capacity. When run with --username --show against a crafted hash file containing an oversized username that nearly fills the buffer, the total assembled output exceeds the buffer, causing a heap buffer overflow that can corrupt memory and crash the process.
Weakness: CWE-120
Which versions are affected by CVE-2026-68768?
How do I fix CVE-2026-68768?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-68768 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-68768 exists.
Sources
Also known as DEBIAN-CVE-2026-68768, GHSA-cm34-rh84-36rf, UBUNTU-CVE-2026-68768.