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

Quick assessment

Affected
hashcat hashcat
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

hashcat 存在一个基于堆的缓冲区溢出（越界写入）漏洞，该漏洞位于 src/outfile.c 文件中的 outfile_write() 函数内。在将输出组装到固定大小的缓冲区（HCBUFSIZ_LARGE，约 16 MB）时，该函数依次通过 memcpy 追加用户名、分隔符、哈希值和明文，但未验证累积长度是否仍在缓冲区容量范围内。当使用 --username --show 选项针对包含超大用户名的构造哈希文件运行，且该用户名几乎填满缓冲区时，最终组装的输出长度会超出缓冲区边界，导致堆缓冲区溢出，从而可能破坏内

CVSS 6.1 · Medium EPSS 0.19% · P8

Affected Version Matrix 1

VendorProduct Version RangeStatus
hashcat hashcat ≤ 7.1.2 affected
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I. Basic Information for CVE-2026-68768

Vulnerability Information
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Vulnerability Title
hashcat through 7.1.2 Heap Buffer Overflow in outfile_write() via Oversized Username
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
未进行输入大小检查的缓冲区拷贝(传统缓冲区溢出)
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
hashcat hashcat 0 ~ 7.1.2 -

II. Public POCs for CVE-2026-68768

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III. Intelligence Information for CVE-2026-68768

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Patches & Fixes for CVE-2026-68768 (1)

Vendor Advisories for CVE-2026-68768 (2)

Proof of Concept for CVE-2026-68768 (1)

Same Patch Batch · hashcat · 2026-08-22 · 3 CVEs total

CVE-2026-68766 7.8 HIGH hashcat through 7.1.2 Arbitrary File Write via Restore File Option Injection
CVE-2026-68767 6.1 MEDIUM hashcat through 7.1.2 Off-by-One Out-of-Bounds Heap Write in fgetl()

IV. Related Vulnerabilities

Same product: hashcat
Same vendor: hashcat
Same weakness: CWE-120

V. Comments for CVE-2026-68768

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