CVE-2026-18739: Memory Corruption (CVSS 2.5)

Description

A flaw was found in popt, a command-line option parsing library. An off-by-one error in the poptStuffArgs function, when repeatedly called by a host application or through deep alias nesting, can lead to corruption of internal program data. This corruption could potentially enable a local attacker to execute arbitrary code if the host application then unsafely processes the altered data.

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CVSS v3.1 Score

2.5

LOW

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L

EPSS — Exploit Prediction

0.0010

Probability of exploitation

0.01%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-787 Out-of-bounds Write

References

Other References

https://access.redhat.com/security/cve/CVE-2026-18739 https://bugzilla.redhat.com/show_bug.cgi?id=2510737

Frequently Asked Questions

What is CVE-2026-18739? +

A flaw was found in popt, a command-line option parsing library. An off-by-one error in the poptStuffArgs function, when repeatedly called by a host application or through deep alias nesting, can lead to corruption of internal program data. This corruption could potentially enable a local attacker to execute arbitrary code if the host application then unsafely processes the altered data. It has a CVSS v3.1 base score of 2.5 (LOW).

How severe is CVE-2026-18739? +

CVE-2026-18739 has a CVSS v3.1 score of 2.5 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0010, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-18739? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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