A stack-based buffer overflow in mangle_to_hex_lower() and mangle_to_hex_upper() in src/rp_cpu.c...

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.

Basic information

Type
unreviewed
Severity
critical
Advisory on GitHub
Open advisory ↗
Repository advisory
Source code
Not specified
Published (advisory)
2026-05-01 15:30:33 UTC
Updated
2026-05-01 21:31:20 UTC
NVD published
2026-05-01

EPSS Score

Score Percentile
0.07% 22.44%

CVSS Scores

Base score Version Severity Vector
9.8 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.

Identifiers

CWEs

CWE id Name
CWE-121 Stack-based Buffer Overflow
CWE-787 Out-of-bounds Write

References

cvelogic Threat Intelligence