CVE-2026-42483: A heap-based buffer overflow in the Kerberos hash parser in hashcat v7.1.2 allows an attacker to cause a denia

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2026-42483 is a critical-severity flaw (CVSS 9.8) affecting hashcat. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A heap-based buffer overflow in the Kerberos hash parser in hashcat v7.1.2 allows an attacker to cause a denial of service or possibly execute arbitrary code via a crafted Kerberos hash file. The issue affects module_hash_decode in multiple Kerberos-related modules because account_info_len is calculated from untrusted delimiter positions without upper-bound validation before memcpy copies the data into a fixed-size account_info buffer.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 77%)
CISA exploited list	No
Weakness	CWE-787, CWE-122
Published	2026-05-01
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: hashcat

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-01 14:16 UTCPublished CVE record published
2026-06-17 10:47 UTCUpdated Record last modified

hashcat hashcat DOWNGRADE

Affected: 7.1.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.1.2

1. Check installed version

apt-cache policy hashcat || rpm -q hashcat || hashcat --version

2. No fixed release: DOWNGRADE to a release before 7.1.2 (Debian / Ubuntu)

apt-cache madison hashcat sudo apt install hashcat=<VERSION_BEFORE_7.1.2> sudo apt-mark hold hashcat

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list hashcat sudo dnf downgrade hashcat-<VERSION_BEFORE_7.1.2> sudo dnf versionlock add hashcat

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-42483?

hashcat: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-42483 being exploited?

CVE-2026-42483 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-42483 affect?

CVE-2026-42483 affects hashcat. Severity is critical (CVSS 9.8). A heap-based buffer overflow in the Kerberos hash parser in hashcat v7.1.2 allows an attacker to cause a denial of service or possibly execute arbitrary code via a crafted Kerberos hash file. The issue affects module_hash_decode in multiple

How urgent is CVE-2026-42483?

Priority 50/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-42484 CRITICAL 9.8 DOWNGRADE A heap-based buffer overflow in hex_to_binary in the PKZIP hash parser in hashcat v7.1.2 allows an attacker to
CVE-2026-42482 CRITICAL 9.8 DOWNGRADE A stack-based buffer overflow in mangle_to_hex_lower() and mangle_to_hex_upper() in src/rp_cpu.c in hashcat v7

References

← Back to latest CVEs