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CVE-2026-18739

LOW 2.5

Published 2026-08-04 · Last modified 2026-08-21

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.

NO EXPLOITATION SIGNALS

No known exploitation, public exploit, or elevated probability at this time. Track for changes.

Exploitation likelihood

0.1%chance of exploitation in 30 days · 1st percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

2.5CVSS 3.1 · LOW

  • ConfidentialityNone
  • IntegrityNone
  • AvailabilityLow

What an attacker needs

  • Access: Requires local access to the host
  • Privileges: Requires a low-privilege account
  • User interaction: No user interaction needed
  • Complexity: Needs a race window or specific setup

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-18739/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-18739/poc.json

Affected

Vendors Rpm Software Management Red Hat

Products Popt Red Hat Hardened Images Red Hat Enterprise Linux 10 Red Hat Enterprise Linux 6 Red Hat Enterprise Linux 7 Red Hat Enterprise Linux 8 Red Hat Enterprise Linux 9 Red Hat Openshift Container Platform 4

Weakness (CWE)

  • CWE-787: Out-of-bounds Write

CVSS vector

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

All CVSS metrics

  • LOW 2.5 v3.1 · CNA Primary
    CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
  • LOW 2.5 v3.1 · NVD Secondary
    CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L

References

Advisories

Technical & other

Sources: NVD · CVE.org · EPSS