CVE-2018-18506

MEDIUMNVD 5.95.9—
EchelonGraph scoreMEDIUM confidence

Score 5.9 from GitHub Security Advisory published 2022-05-13. NVD baseline CVSS 5.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.9
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 2%CVSS: 5.9Exploit: NoneExposed: 0

A fix is available — apply it.

When proxy auto-detection is enabled, if a web server serves a Proxy Auto-Configuration (PAC) file or if a PAC file is loaded locally, this PAC file can specify that requests to the localhost are to be sent through the proxy to another server. This behavior is disallowed by default when a proxy is manually configured, but when enabled could allow for attacks on services and tools that bind to the localhost for networked behavior if they are accessed through browsing. This vulnerability affects Firefox < 65.

CVSS v3
5.9
EG Score
5.9(medium)
EPSS
80.2%
KEV
Not listed

Published

February 5, 2019

Last Modified

November 21, 2024

References (42)

Vendor Advisories for CVE-2018-18506(6)

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

Patch Availability(8)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuxul-ext-lightning (1:60.6.1+build2-0ubuntu0.18.10.1) @ cosmic2026-05-27ubuntu
ubuntufirefox-testsuite (65.0+build2-0ubuntu0.16.04.1) @ xenial2026-05-27ubuntu
redhatthunderbird-0:60.6.1-1.el82019-05-13redhat
redhatfirefox-0:60.6.1-1.el82019-05-07redhat
redhatthunderbird-0:60.6.1-1.el7_62019-03-28redhat
redhatthunderbird-0:60.6.1-1.el6_102019-03-28redhat
redhatfirefox-0:60.6.0-3.el7_62019-03-20redhat
redhatfirefox-0:60.6.0-3.el6_102019-03-20redhat

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.

Additional Vendor Advisories

(2)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 14× in last 7d / 50× 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. 2026-07-07 13:42 UTCEPSS rescore
  2. 2026-07-07 13:42 UTCEPSS rescore
  3. 2026-07-06 16:24 UTCEPSS rescore
  4. 2026-07-06 16:24 UTCEPSS rescore
  5. 2026-07-06 02:20 UTCEPSS rescore
  6. 2026-07-05 02:27 UTCEPSS rescore
  7. 2026-07-04 06:28 UTCEPSS rescore
  8. 2026-07-04 06:28 UTCEPSS rescore
  9. 2026-07-03 18:26 UTCOSV refresh
  10. 2026-07-02 16:54 UTCEPSS rescore
  11. 2026-07-01 15:03 UTCEPSS rescore
  12. 2026-07-01 15:03 UTCEPSS rescore
  13. 2026-06-30 23:20 UTCEPSS rescore
  14. 2026-06-30 23:19 UTCEPSS rescore
  15. 2026-06-29 14:03 UTCEPSS rescore
  16. 2026-06-28 14:04 UTCEPSS rescore
  17. 2026-06-28 04:53 UTCEPSS rescore
  18. 2026-06-28 04:53 UTCEPSS rescore
  19. 2026-06-27 03:06 UTCEPSS rescore
  20. 2026-06-27 03:06 UTCEPSS rescore
  21. 2026-06-25 13:47 UTCEPSS rescore
  22. 2026-06-25 13:47 UTCEPSS rescore
  23. 2026-06-24 14:02 UTCEPSS rescore
  24. 2026-06-24 14:02 UTCEPSS rescore
  25. 2026-06-23 21:30 UTCEPSS rescore
Show 53 more
  1. 2026-06-23 21:30 UTCEPSS rescore
  2. 2026-06-23 21:30 UTCEPSS rescore
  3. 2026-06-22 14:23 UTCEPSS rescore
  4. 2026-06-21 14:54 UTCEPSS rescore
  5. 2026-06-21 14:54 UTCEPSS rescore
  6. 2026-06-19 19:23 UTCEPSS rescore
  7. 2026-06-19 19:23 UTCEPSS rescore
  8. 2026-06-18 17:50 UTCEPSS rescore
  9. 2026-06-18 17:50 UTCEPSS rescore
  10. 2026-06-17 17:50 UTCEPSS rescore
  11. 2026-06-17 17:50 UTCEPSS rescore
  12. 2026-06-16 17:50 UTCEPSS rescore
  13. 2026-06-16 17:50 UTCEPSS rescore
  14. 2026-06-15 17:45 UTCEPSS rescore
  15. 2026-06-15 06:43 UTCOSV refresh
  16. 2026-06-14 23:15 UTCEPSS rescore
  17. 2026-06-14 23:14 UTCEPSS rescore
  18. 2026-06-13 22:58 UTCEPSS rescore
  19. 2026-06-12 23:09 UTCEPSS rescore
  20. 2026-06-12 23:09 UTCEPSS rescore
  21. 2026-06-11 13:57 UTCEPSS rescore
  22. 2026-06-10 22:16 UTCEPSS rescore
  23. 2026-06-10 13:19 UTCEPSS rescore
  24. 2026-06-08 14:14 UTCEPSS rescore
  25. 2026-06-08 14:14 UTCEPSS rescore
  26. 2026-06-07 15:22 UTCEPSS rescore
  27. 2026-06-07 15:22 UTCEPSS rescore
  28. 2026-06-06 13:45 UTCEPSS rescore
  29. 2026-06-06 13:45 UTCEPSS rescore
  30. 2026-06-05 22:45 UTCEPSS rescore
  31. 2026-06-05 22:45 UTCEPSS rescore
  32. 2026-06-05 06:08 UTCEPSS rescore
  33. 2026-06-05 06:08 UTCEPSS rescore
  34. 2026-06-04 13:10 UTCEPSS rescore
  35. 2026-06-02 20:11 UTCEPSS rescore
  36. 2026-06-02 20:11 UTCEPSS rescore
  37. 2026-06-01 13:50 UTCEPSS rescore
  38. 2026-06-01 13:50 UTCEPSS rescore
  39. 2026-05-31 22:29 UTCEPSS rescore
  40. 2026-05-31 00:14 UTCEPSS rescore
  41. 2026-05-31 00:14 UTCEPSS rescore
  42. 2026-05-29 13:41 UTCEPSS rescore
  43. 2026-05-28 13:42 UTCEPSS rescore
  44. 2026-05-28 13:42 UTCEPSS rescore
  45. 2026-05-27 22:43 UTCEG score recompute
  46. 2026-05-27 22:43 UTCVendor advisory
  47. 2026-05-27 22:43 UTCGHSA enrichment
  48. 2026-05-27 13:38 UTCEPSS rescore
  49. 2026-05-27 13:38 UTCEPSS rescore
  50. 2026-05-26 13:42 UTCEPSS rescore
  51. 2026-05-26 13:42 UTCEPSS rescore
  52. 2026-05-26 07:17 UTCEPSS rescore
  53. 2026-05-26 07:17 UTCEPSS rescore

Related CVEs(same vendor)

Frequently asked(5)

What is CVE-2018-18506?
CVE-2018-18506 is a medium vulnerability published on February 5, 2019. When proxy auto-detection is enabled, if a web server serves a Proxy Auto-Configuration (PAC) file or if a PAC file is loaded locally, this PAC file can specify that requests to the localhost are to be sent through the proxy to another server. This behavior is disallowed by default when a proxy is…
When was CVE-2018-18506 disclosed?
CVE-2018-18506 was first published in the National Vulnerability Database on February 5, 2019, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2018-18506 actively exploited?
CVE-2018-18506 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 80.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2018-18506?
CVE-2018-18506 has a CVSS v3 base score of 5.9 (NVD).
How do I remediate CVE-2018-18506?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2018-18506, 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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