CVE-2026-18839
LOW 2.2An integer underflow was found in the popt library when formatting help text for option tables that exceed the terminal width. A local user who can cause an application to print help under those conditions may cause that application to crash or fail to display help, resulting in a denial of service of the affected application.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.1%chance of exploitation in 30 days · 0th percentile
Impact if exploited
2.2CVSS 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: A user must take an action (click / open a file)
- ⚠Complexity: Needs a race window or specific setup
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-18839/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-2026-18839/poc.json
Affected
Vendors Rpm Software Management Red Hat
Products Popt 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 Hardened Images Red Hat Openshift Container Platform 4
Weakness (CWE)
- CWE-191: Integer Underflow (Wrap or Wraparound)
CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L
All CVSS metrics
- LOW 2.2 v3.1 · CNA Primary
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L - LOW 2.2 v3.1 · NVD Secondary
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L