CVE-2026-68768
hashcat through 7.1.2 Heap Buffer Overflow in outfile_write() via Oversized Username
- State
- Published
- Severity
- 6.9 Medium
- Published
- Aug 22, 2026
- Updated
- Aug 24, 2026
- Reserved
- Jul 31, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.9 Medium | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 6.1 Medium | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H | VulnCheck |
Weaknesses
- CWE-120 Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Affected Products
| Product | Versions |
|---|---|
hashcathashcat |
|
References
- GitHub Issue #4740issue-tracking
- https://github.com/hashcat/hashcatproduct
- https://github.com/hashcat/hashcat/commit/68f56a2d8712867a8520bf4dcf07f6145c23df89patch
- https://github.com/hashcat/hashcat/blob/v7.1.2/src/outfile.c#L654-L668technical-description
- VulnCheck Advisory: hashcat through 7.1.2 Heap Buffer Overflow in outfile_write() via Oversized Usernamethird-party-advisory
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.