CVE-2026-42482

Stack-based Buffer Overflow in hashcat’s Hex Mangle Functions Allowing Potential Code Execution

Published May 1, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
A stack-based buffer overflow in mangle_to_hex_lower() and mangle_to_hex_upper() in src/rp_cpu.c in hashcat v7.1.2 allows an attacker to cause a denial of service or possibly execute arbitrary code via a crafted rule file, or via the -j or -k rule options used with password candidates of 128 or more characters. The vulnerability is caused by a bounds check that fails to account for the 2x expansion that occurs when password bytes are converted to hexadecimal.

Analysis

AI-generated

Technical impact

A stack-based buffer overflow exists in the hex‑mangle functions of hashcat, allowing an attacker to crash the program or, possibly, execute arbitrary code by supplying a specially crafted rule file or using the -j or -k options with password candidates of 128 or more characters. The flaw is caused by a bounds check that does not account for the two‑times expansion of password bytes when converted to hexadecimal.

Affected Systems

hashcat version 7.1.2 is affected. The issue was identified in the source functions used during rule application, so any environment deploying that specific version and using the rule options described may be vulnerable. No other product or version data was provided in the advisory.

Risk and Exploitability

The CVSS score is 7.5, the EPSS score is not available, so the likelihood of exploitation is unclear from the data. However, because the vulnerability can be triggered by a crafted rule file or certain command options, environments that routinely run hashcat with user‑supplied rules or long password candidates face a definite risk. The vulnerability is not currently in the CISA KEV catalog, but the potential for arbitrary code execution means it deserves prompt attention.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade hashcat to the latest available version to remove the flaw.
  • Avoid using the -j or -k rule options with password candidates of 128 bytes or more until a patched version is deployed.
  • If an upgrade is delayed, restrict rule file usage to trusted sources, monitor for crashes, and consider disabling rule options during critical operations.

Generated by OpenCVE AI on May 2, 2026 at 08:02 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Title Stack-based Buffer Overflow in hashcat’s Hex Mangle Functions Allowing Potential Code Execution
Type Values Removed Values Added
Weaknesses CWE-121
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Type Values Removed Values Added
First Time appeared Hashcat
Hashcat hashcat
Weaknesses CWE-787
CPEs cpe:2.3:a:hashcat:hashcat:7.1.2:*:*:*:*:*:*:*
Vendors & Products Hashcat
Hashcat hashcat
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Description A stack-based buffer overflow in mangle_to_hex_lower() and mangle_to_hex_upper() in src/rp_cpu.c in hashcat v7.1.2 allows an attacker to cause a denial of service or possibly execute arbitrary code via a crafted rule file, or via the -j or -k rule options used with password candidates of 128 or more characters. The vulnerability is caused by a bounds check that fails to account for the 2x expansion that occurs when password bytes are converted to hexadecimal.
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
May 1, 2026, 6:36 PM
Reserved
Apr 27, 2026, 12:00 AM
Status
Modified
Published
May 1, 2026, 2:16 PM
Modified
Nov 11, 2026, 9:10 PM