CVE-2025-67125: A signed integer overflow in docopt.cpp v0.6.2 (LeafPattern::match in docopt_private.h) when merging occurrenc

Routine

MEDIUM 4.4DOWNGRADE

CVE-2025-67125 is a medium-severity flaw (CVSS 4.4) affecting docopt.cpp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A signed integer overflow in docopt.cpp v0.6.2 (LeafPattern::match in docopt_private.h) when merging occurrence counters (e.g., default LONG_MAX + first user "-v/--verbose") can cause counter wrap (negative/unbounded semantics) and lead to logic/policy bypass in applications that rely on occurrence-based limits, rate-gating, or safety toggles. In hardened builds (e.g., UBSan or -ftrapv), the overflow may also result in process abort (DoS).

Why this priority

Public exploit reference

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

Risk facts

CVSS score	4.4 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 85%)
CISA exploited list	No
Weakness	CWE-190
Published	2026-01-23
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: docopt

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

Am I affected?

Timeline

2026-01-23 16:15 UTCPublished CVE record published
2026-06-17 09:57 UTCUpdated Record last modified

docopt docopt.cpp DOWNGRADE

Affected: 0.6.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.6.2

1. Check installed version

apt-cache policy docopt.cpp || rpm -q docopt.cpp || docopt.cpp --version

2. No fixed release: DOWNGRADE to a release before 0.6.2 (Debian / Ubuntu)

apt-cache madison docopt.cpp sudo apt install docopt.cpp=<VERSION_BEFORE_0.6.2> sudo apt-mark hold docopt.cpp

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

dnf --showduplicates list docopt.cpp sudo dnf downgrade docopt.cpp-<VERSION_BEFORE_0.6.2> sudo dnf versionlock add docopt.cpp

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-2025-67125?

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

Is CVE-2025-67125 being exploited?

CVE-2025-67125 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-2025-67125 affect?

CVE-2025-67125 affects docopt.cpp. Severity is medium (CVSS 4.4). A signed integer overflow in docopt.cpp v0.6.2 (LeafPattern::match in docopt_private.h) when merging occurrence counters (e.g., default LONG_MAX + first user "-v/--verbose") can cause counter wrap (negative/unbounded semantics) and lead to

How urgent is CVE-2025-67125?

Priority 24/100. Public exploit reference

References

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