CVE-2026-18839

LOWPre-NVD 2.22.2—
EchelonGraph scoreMEDIUM confidence

Score 2.2 from GitHub Security Advisory (severity: LOW) published 2026-08-05. a secondary CVSS source baseline 2.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
2.2EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 2.2Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

An 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.

CVSS v3
2.2
EG Score
2.2(medium)
EG Risk
10(Track)
EG Risk 10/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity22% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
0%
KEV
Not listed

Published

August 5, 2026

Last Modified

September 1, 2026

References (2)

Vendor Advisories for CVE-2026-18839(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
popt1.18-2, 1.18-3, 1.19+dfsg-1, 1.19+dfsg-1~exp1, 1.19+dfsg-2——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
popt1.19+dfsg-1, 1.19+dfsg-2——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
popt1.19+dfsg-2——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
popt1.19+dfsg-2——

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 45× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-17 01:04 UTCEG score recompute
  2. 2026-09-17 01:04 UTCVendor advisory
  3. 2026-09-17 01:04 UTCGHSA enrichment
  4. 2026-09-16 14:07 UTCEPSS rescore
  5. 2026-09-16 05:14 UTCEPSS rescore
  6. 2026-09-13 22:14 UTCEG score recompute
  7. 2026-09-13 22:14 UTCVendor advisory
  8. 2026-09-13 22:14 UTCGHSA enrichment
  9. 2026-09-12 15:00 UTCEPSS rescore
  10. 2026-09-11 14:52 UTCEPSS rescore
  11. 2026-09-11 09:36 UTCEPSS rescore
  12. 2026-09-10 20:12 UTCEG score recompute
  13. 2026-09-10 20:12 UTCGHSA enrichment
  14. 2026-09-10 09:34 UTCEPSS rescore
  15. 2026-09-08 22:00 UTCEPSS rescore
  16. 2026-09-07 18:10 UTCEG score recompute
  17. 2026-09-07 18:10 UTCGHSA enrichment
  18. 2026-09-06 13:47 UTCEPSS rescore
  19. 2026-09-04 15:53 UTCEG score recompute
  20. 2026-09-04 15:53 UTCGHSA enrichment
  21. 2026-09-04 05:06 UTCEPSS rescore
  22. 2026-09-01 13:53 UTCEPSS rescore
  23. 2026-09-01 13:42 UTCEG score recompute
  24. 2026-09-01 13:42 UTCGHSA enrichment
  25. 2026-09-01 13:17 UTCEG score recompute
Show 46 more
  1. 2026-09-01 13:17 UTCGHSA enrichment
  2. 2026-09-01 04:39 UTCEPSS rescore
  3. 2026-08-31 16:40 UTCEG score recompute
  4. 2026-08-31 16:40 UTCGHSA enrichment
  5. 2026-08-31 15:38 UTCEG score recompute
  6. 2026-08-31 15:38 UTCGHSA enrichment
  7. 2026-08-30 21:55 UTCGHSA enrichment
  8. 2026-08-27 19:54 UTCEG score recompute
  9. 2026-08-27 19:54 UTCGHSA enrichment
  10. 2026-08-27 14:25 UTCEPSS rescore
  11. 2026-08-26 14:46 UTCEPSS rescore
  12. 2026-08-25 13:48 UTCEPSS rescore
  13. 2026-08-24 15:23 UTCEG score recompute
  14. 2026-08-24 15:22 UTCGHSA enrichment
  15. 2026-08-23 00:19 UTCEPSS rescore
  16. 2026-08-21 23:49 UTCEPSS rescore
  17. 2026-08-21 13:21 UTCEG score recompute
  18. 2026-08-21 13:21 UTCGHSA enrichment
  19. 2026-08-21 13:09 UTCEG score recompute
  20. 2026-08-21 13:09 UTCGHSA enrichment
  21. 2026-08-19 17:03 UTCEPSS rescore
  22. 2026-08-18 23:53 UTCEG score recompute
  23. 2026-08-18 23:53 UTCGHSA enrichment
  24. 2026-08-18 13:48 UTCEPSS rescore
  25. 2026-08-17 13:47 UTCEPSS rescore
  26. 2026-08-16 02:14 UTCEPSS rescore
  27. 2026-08-15 21:52 UTCGHSA enrichment
  28. 2026-08-12 19:50 UTCEG score recompute
  29. 2026-08-12 19:50 UTCGHSA enrichment
  30. 2026-08-12 13:50 UTCEPSS rescore
  31. 2026-08-09 17:49 UTCEG score recompute
  32. 2026-08-09 17:49 UTCGHSA enrichment
  33. 2026-08-08 16:37 UTCEPSS rescore
  34. 2026-08-06 15:48 UTCGHSA enrichment
  35. 2026-08-06 14:17 UTCEG score recompute
  36. 2026-08-06 14:17 UTCGHSA enrichment
  37. 2026-08-06 13:53 UTCEG score recompute
  38. 2026-08-06 13:53 UTCGHSA enrichment
  39. 2026-08-06 13:46 UTCEPSS rescore
  40. 2026-08-05 22:18 UTCEG score recompute
  41. 2026-08-05 22:18 UTCGHSA enrichment
  42. 2026-08-05 22:05 UTCEG score recompute
  43. 2026-08-05 22:05 UTCGHSA enrichment
  44. 2026-08-05 21:17 UTCEG score recompute
  45. 2026-08-05 21:10 UTCEG score recompute
  46. 2026-08-05 21:10 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-18839?
CVE-2026-18839 is a low vulnerability published on August 5, 2026. An 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…
When was CVE-2026-18839 disclosed?
CVE-2026-18839 was first published in the National Vulnerability Database on August 5, 2026, with the most recent update on September 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18839 actively exploited?
CVE-2026-18839 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 99.7% of all scored CVEs.
What is the CVSS score of CVE-2026-18839?
CVE-2026-18839 has a CVSS v3 base score of 2.2 (NVD).
How do I remediate CVE-2026-18839?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18839, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-18839

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