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OpenAdvisories
Medium · 6.1 CVE-2026-68768 EUVD-2026-64313GHSA-cm34-rh84-36rf

hashcat through 7.1.2 Heap Buffer Overflow in outfile_write() via Oversized Username

Published Aug 22, 2026 · Updated Aug 24, 2026 · Assigned by VulnCheck

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.

Affected products

VendorProductAffectedFixed
hashcat hashcat ≤ 7.1.2 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 hashcat No fix yet —
Debian 13 hashcat No fix yet —
Debian 12 hashcat No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 hashcat No fix yet —
Ubuntu 26.04 LTS hashcat No fix yet —
Ubuntu 24.04 LTS hashcat No fix yet —
Ubuntu 22.04 LTS hashcat No fix yet —
Ubuntu 20.04 LTS hashcat No fix yet —
Show 1 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 18.04 LTS hashcat No fix yet —
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed hashcat 7.1.2+git942-1.1 openSUSE-SU-2026:12181-1
openSUSE Leap 16.0 hashcat 7.1.2+git942-bp160.1.1 openSUSE-SU-2026:22138-1

Advisories 2

References