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.
CSIRTS triage
- What
- poptstuffargs function contains an off-by-one error in buffer handling.
- Who is affected
- Applications linked against vulnerable Popt library versions.
- Urgency
- Low; off-by-one errors may enable local exploitation under specific conditions.
- Action
- Update to a patched Popt version that corrects the off-by-one buffer logic.
AI-assisted analysis generated from the source advisory — verify against the original.
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Exploitation outlook
- Low exploitation risk0.11% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 1% of all EPSS-scored CVEs.
Advisory coverage (2)
External references
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[](https://www.csirts.com/cve/CVE-2026-18739)