CVE-2026-18739

LOWPre-NVD 2.52.5—
EchelonGraph scoreMEDIUM confidence

Score 2.5 from GitHub Security Advisory (severity: LOW) published 2026-08-04. a secondary CVSS source baseline 2.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
2.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 2.5Exploit: None knownExposed: 0

A fix is available — apply it.

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.

CVSS v3
2.5
EG Score
2.5(medium)
EG Risk
11(Track)
EG Risk 11/100SSVC: 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
Severity25% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
1%
KEV
Not listed

Published

August 4, 2026

Last Modified

August 31, 2026

References (3)

Vendor Advisories for CVE-2026-18739(3)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatpopt-main-1.19-11.1.hum12026-08-19redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

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 10× in last 7d / 61× 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.

Showing the most recent 100 of 111 total refreshes for this CVE.

  1. 2026-09-18 19:27 UTCEPSS rescore
  2. 2026-09-18 03:44 UTCEG score recompute
  3. 2026-09-18 03:44 UTCVendor advisory
  4. 2026-09-18 03:44 UTCGHSA enrichment
  5. 2026-09-16 14:07 UTCEPSS rescore
  6. 2026-09-16 05:14 UTCEPSS rescore
  7. 2026-09-15 06:59 UTCEG score recompute
  8. 2026-09-15 06:59 UTCVendor advisory
  9. 2026-09-15 06:59 UTCGHSA enrichment
  10. 2026-09-13 16:46 UTCEPSS rescore
  11. 2026-09-12 07:59 UTCEG score recompute
  12. 2026-09-12 07:59 UTCVendor advisory
  13. 2026-09-12 07:59 UTCGHSA enrichment
  14. 2026-09-11 14:52 UTCEPSS rescore
  15. 2026-09-11 09:36 UTCEPSS rescore
  16. 2026-09-10 09:34 UTCEPSS rescore
  17. 2026-09-09 11:02 UTCEG score recompute
  18. 2026-09-09 11:02 UTCVendor advisory
  19. 2026-09-09 11:02 UTCGHSA enrichment
  20. 2026-09-08 22:00 UTCEPSS rescore
  21. 2026-09-07 16:01 UTCEPSS rescore
  22. 2026-09-06 14:17 UTCEG score recompute
  23. 2026-09-06 14:17 UTCVendor advisory
  24. 2026-09-06 14:17 UTCGHSA enrichment
  25. 2026-09-06 13:47 UTCEPSS rescore
Show 75 more
  1. 2026-09-04 05:06 UTCEPSS rescore
  2. 2026-09-03 17:33 UTCEG score recompute
  3. 2026-09-03 17:33 UTCVendor advisory
  4. 2026-09-03 17:32 UTCGHSA enrichment
  5. 2026-09-01 13:53 UTCEPSS rescore
  6. 2026-08-31 18:36 UTCEG score recompute
  7. 2026-08-31 18:36 UTCVendor advisory
  8. 2026-08-31 18:35 UTCGHSA enrichment
  9. 2026-08-31 17:31 UTCVendor advisory
  10. 2026-08-31 17:31 UTCGHSA enrichment
  11. 2026-08-31 16:40 UTCVendor advisory
  12. 2026-08-31 16:40 UTCGHSA enrichment
  13. 2026-08-31 15:39 UTCEG score recompute
  14. 2026-08-31 15:39 UTCVendor advisory
  15. 2026-08-31 15:39 UTCGHSA enrichment
  16. 2026-08-30 19:17 UTCEPSS rescore
  17. 2026-08-30 05:13 UTCEG score recompute
  18. 2026-08-30 05:13 UTCVendor advisory
  19. 2026-08-30 05:13 UTCGHSA enrichment
  20. 2026-08-30 01:22 UTCEPSS rescore
  21. 2026-08-28 21:41 UTCEPSS rescore
  22. 2026-08-27 14:25 UTCEPSS rescore
  23. 2026-08-27 08:28 UTCEG score recompute
  24. 2026-08-27 08:28 UTCVendor advisory
  25. 2026-08-27 08:28 UTCGHSA enrichment
  26. 2026-08-26 14:46 UTCEPSS rescore
  27. 2026-08-24 10:06 UTCEG score recompute
  28. 2026-08-24 10:06 UTCVendor advisory
  29. 2026-08-24 10:06 UTCGHSA enrichment
  30. 2026-08-21 13:21 UTCEG score recompute
  31. 2026-08-21 13:21 UTCVendor advisory
  32. 2026-08-21 13:21 UTCGHSA enrichment
  33. 2026-08-21 13:09 UTCEG score recompute
  34. 2026-08-21 13:09 UTCVendor advisory
  35. 2026-08-21 13:09 UTCGHSA enrichment
  36. 2026-08-20 22:55 UTCEPSS rescore
  37. 2026-08-19 17:03 UTCEPSS rescore
  38. 2026-08-19 14:34 UTCEG score recompute
  39. 2026-08-19 14:34 UTCGHSA enrichment
  40. 2026-08-19 13:40 UTCEG score recompute
  41. 2026-08-19 13:40 UTCGHSA enrichment
  42. 2026-08-18 13:48 UTCEPSS rescore
  43. 2026-08-18 03:39 UTCEG score recompute
  44. 2026-08-18 03:39 UTCGHSA enrichment
  45. 2026-08-17 13:47 UTCEPSS rescore
  46. 2026-08-16 14:56 UTCEPSS rescore
  47. 2026-08-16 02:14 UTCEPSS rescore
  48. 2026-08-15 06:55 UTCEG score recompute
  49. 2026-08-15 06:55 UTCGHSA enrichment
  50. 2026-08-15 01:30 UTCEPSS rescore
  51. 2026-08-13 22:00 UTCEPSS rescore
  52. 2026-08-12 09:19 UTCEG score recompute
  53. 2026-08-12 09:19 UTCGHSA enrichment
  54. 2026-08-11 13:42 UTCEPSS rescore
  55. 2026-08-11 00:00 UTCEPSS rescore
  56. 2026-08-09 13:46 UTCEPSS rescore
  57. 2026-08-09 12:35 UTCEG score recompute
  58. 2026-08-09 12:35 UTCGHSA enrichment
  59. 2026-08-08 16:37 UTCEPSS rescore
  60. 2026-08-06 15:50 UTCEG score recompute
  61. 2026-08-06 15:50 UTCGHSA enrichment
  62. 2026-08-06 13:46 UTCEPSS rescore
  63. 2026-08-05 22:18 UTCEG score recompute
  64. 2026-08-05 22:18 UTCGHSA enrichment
  65. 2026-08-05 22:05 UTCEG score recompute
  66. 2026-08-05 22:05 UTCGHSA enrichment
  67. 2026-08-05 19:17 UTCEPSS rescore
  68. 2026-08-05 19:01 UTCEG score recompute
  69. 2026-08-05 19:01 UTCGHSA enrichment
  70. 2026-08-05 05:26 UTCEG score recompute
  71. 2026-08-05 05:25 UTCGHSA enrichment
  72. 2026-08-05 04:36 UTCEG score recompute
  73. 2026-08-05 04:36 UTCGHSA enrichment
  74. 2026-08-05 00:20 UTCGHSA enrichment
  75. 2026-08-04 23:18 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-18739?
CVE-2026-18739 is a low vulnerability published on August 4, 2026. 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…
When was CVE-2026-18739 disclosed?
CVE-2026-18739 was first published in the National Vulnerability Database on August 4, 2026, with the most recent update on August 31, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18739 actively exploited?
CVE-2026-18739 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 98.8% of all scored CVEs.
What is the CVSS score of CVE-2026-18739?
CVE-2026-18739 has a CVSS v3 base score of 2.5 (NVD).
How do I remediate CVE-2026-18739?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18739, 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.

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