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.

Attack Vector Local

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction Passive

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Local

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact Low

Availability Impact High

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
hashcat hashcat unaffected
Version Status Constraints
0 affected ≤ 7.1.2

No data.

No data.

No data.

Project Subscriptions

Vendors Products
Hashcat Subscribe
Hashcat Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

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

Sat, 22 Aug 2026 14:30:00 +0000

Type Values Removed Values Added
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.
Title hashcat through 7.1.2 Heap Buffer Overflow in outfile_write() via Oversized Username
First Time appeared Hashcat
Hashcat hashcat
Weaknesses CWE-120
CPEs cpe:2.3:a:hashcat:hashcat:*:*:*:*:*:*:*:*
Vendors & Products Hashcat
Hashcat hashcat
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H'}

cvssV4_0

{'score': 6.9, 'vector': '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'}

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-22T14:12:44.241Z

Reserved: 2026-07-31T16:10:55.447Z

Link: CVE-2026-68768

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses