What’s Vulnerable › Vulnerabilities

CVE-2026-68768: hashcat through 7.1.2 Heap Buffer Overflow in outfile_write() via Oversized Username

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-22 · updated 2026-10-14
• Weakness: CWE-120

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

• hashcat: through 7.1.2

References

• https://github.com/hashcat/hashcat
• https://github.com/hashcat/hashcat/blob/v7.1.2/src/outfile.c#L654-L668
• https://github.com/hashcat/hashcat/commit/68f56a2d8712867a8520bf4dcf07f6145c23df89
• https://github.com/hashcat/hashcat/issues/4740
• https://www.vulncheck.com/advisories/hashcat-through-heap-buffer-overflow-in-outfile-write-via-oversized-username
• https://github.com/hashcat/hashcat/issues/4740

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