CVE-2026-4786

HIGHPre-NVD 7.17.0▼
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.0 under NVD CVSS v3. EPSS exploit probability: 0.0%, top 94% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
7.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.1Exploit: NoneExposed: 0

A fix is available — apply it.

Mitgation of CVE-2026-4519 was incomplete. If the URL contained "%action" the mitigation could be bypassed for certain browser types the "webbrowser.open()" API could have commands injected into the underlying shell. See CVE-2026-4519 for details.

CVSS v3
7.1
EG Score
7.0(medium)
EPSS
20.9%
KEV
Not listed

Published

April 13, 2026

Last Modified

July 15, 2026

Advisory Details (8)

Auto-updated Apr 29, 2026
No patch confirmed yet.
generic

Mailman 3 [CVE-2026-4786] Incomplete mitigation of CVE-2026-4519, %action expansion for command injection to webbrowser.open() - Security-announce - python.org

https://mail.python.org/archives/list/[email protected]/thread/JQDUNJVB4AQNTJECSUKOBDU3XCJIPSE5/
generic

gh-148169: Fix webbrowser `%action` substitution bypass of dash-prefix check by StanFromIreland · Pull Request #148170 · python/cpython · GitHub

https://github.com/python/cpython/pull/148170
generic

`webbrowser`: `%action` substitution can bypass the dash-prefix check · Issue #148169 · python/cpython · GitHub

https://github.com/python/cpython/issues/148169
generic

[3.11] gh-148169: Fix webbrowser `%action` substitution bypass of das… · python/cpython@f465482 · GitHub

https://github.com/python/cpython/commit/f4654824ae0850ac87227fb270f9057477946769
generic

[3.13] gh-148169: Fix webbrowser `%action` substitution bypass of das… · python/cpython@d6d6849 · GitHub

https://github.com/python/cpython/commit/d6d68494be70bdbda20f89f83801ba52ec37daa4
generic

gh-148169: Fix webbrowser `%action` substitution bypass of dash-prefi… · python/cpython@d22922c · GitHub

https://github.com/python/cpython/commit/d22922c8a7958353689dc4763dd72da2dea03fff
generic

[3.10] gh-148169: Fix webbrowser `%action` substitution bypass of das… · python/cpython@c5767a7 · GitHub

https://github.com/python/cpython/commit/c5767a72838a8dda9d6dc5d3558075b055c56bca
generic

[3.14] gh-148169: Fix webbrowser `%action` substitution bypass of das… · python/cpython@28b4ad3 · GitHub

https://github.com/python/cpython/commit/28b4ad38067bbdad34edfcd03ad2de5f06387e53

Vendor Advisories for CVE-2026-4786(20)

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

Patch Availability(30)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhaiis/model-opt-cuda-rhel9:17806819842026-06-10redhat
redhatpython-0:2.6.6-70.el6_10.42026-06-01redhat
redhatpython3.9-0:3.9.18-3.el9_4.132026-05-28redhat
redhatrhui5/rhua-rhel9:17797982222026-05-27redhat
redhatpython3.9-0:3.9.16-1.el9_2.142026-05-20redhat
redhatpython3.9-0:3.9.21-2.el9_6.62026-05-20redhat
redhatpython-0:2.7.5-94.el7_9.52026-05-20redhat
redhatpython3-0:3.6.8-39.el8_4.112026-05-20redhat
redhatpython3-0:3.6.8-51.el8_8.152026-05-20redhat
redhatpython3.9-0:3.9.10-4.el9_0.112026-05-20redhat
redhatpython3.12-0:3.12.13-2.el10_22026-05-19redhat
redhatpython3.9-0:3.9.25-7.el9_82026-05-19redhat
redhatpython3.11-0:3.11.13-9.el9_82026-05-19redhat
redhatpython3.14-0:3.14.4-2.el9_82026-05-19redhat
redhatpython3.14-0:3.14.4-2.el10_22026-05-19redhat
redhatpython3.12-0:3.12.13-2.el9_82026-05-19redhat
redhatpython3-0:3.6.8-47.el8_6.132026-05-14redhat
redhatpython3.12-0:3.12.1-4.el9_4.132026-05-14redhat
redhatpython3.12-0:3.12.9-2.el10_0.92026-05-13redhat
redhatpython3.11-0:3.11.11-2.el9_6.72026-05-07redhat
redhatpython3.11-0:3.11.7-1.el9_4.132026-05-07redhat
redhatpython3.12-0:3.12.9-1.el9_6.82026-05-07redhat
redhatpython3.11-0:3.11.2-2.el9_2.122026-05-05redhat
redhatrhpam-7/rhpam-smartrouter-rhel8:7.13.5-4.17773257082026-05-05redhat
redhatrhui5/rhua-tp-rhel9:17774595042026-04-29redhat
redhatpython3.11-0:3.11.13-7.el8_102026-04-27redhat
redhatpython3.11-0:3.11.13-5.3.el9_72026-04-27redhat
redhatpython3-0:3.6.8-76.el8_102026-04-27redhat
redhatpython3.12-0:3.12.12-4.el9_7.32026-04-27redhat
redhatpython3.9-0:3.9.25-3.el9_7.32026-04-27redhat

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.

Weakness Classification(2)

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

Additional Vendor Advisories

(24)

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 11× in last 7d / 41× 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 113 total refreshes for this CVE.

  1. 2026-07-15 16:57 UTCEPSS rescore
  2. 2026-07-15 16:57 UTCEPSS rescore
  3. 2026-07-15 02:00 UTCEPSS rescore
  4. 2026-07-15 02:00 UTCEPSS rescore
  5. 2026-07-13 22:31 UTCEPSS rescore
  6. 2026-07-13 06:13 UTCEPSS rescore
  7. 2026-07-13 06:13 UTCEPSS rescore
  8. 2026-07-12 05:46 UTCEPSS rescore
  9. 2026-07-11 08:27 UTCEPSS rescore
  10. 2026-07-11 08:27 UTCEPSS rescore
  11. 2026-07-09 19:10 UTCEPSS rescore
  12. 2026-07-08 15:16 UTCEPSS rescore
  13. 2026-07-07 13:46 UTCEPSS rescore
  14. 2026-07-06 16:27 UTCEPSS rescore
  15. 2026-07-06 02:23 UTCEPSS rescore
  16. 2026-07-05 02:30 UTCEPSS rescore
  17. 2026-07-01 15:07 UTCEPSS rescore
  18. 2026-06-30 23:22 UTCEPSS rescore
  19. 2026-06-30 04:32 UTCNVD updateCVSS v3 → 7.1
  20. 2026-06-29 14:06 UTCEPSS rescore
  21. 2026-06-29 14:06 UTCEPSS rescore
  22. 2026-06-28 14:07 UTCEPSS rescore
  23. 2026-06-28 04:56 UTCEPSS rescore
  24. 2026-06-28 04:56 UTCEPSS rescore
  25. 2026-06-27 03:08 UTCEPSS rescore
Show 75 more
  1. 2026-06-25 13:49 UTCEPSS rescore
  2. 2026-06-24 14:05 UTCEPSS rescore
  3. 2026-06-23 21:33 UTCEPSS rescore
  4. 2026-06-23 21:33 UTCEPSS rescore
  5. 2026-06-22 14:25 UTCEPSS rescore
  6. 2026-06-22 14:25 UTCEPSS rescore
  7. 2026-06-21 14:56 UTCEPSS rescore
  8. 2026-06-21 14:56 UTCEPSS rescore
  9. 2026-06-21 01:59 UTCEPSS rescore
  10. 2026-06-21 01:59 UTCEPSS rescore
  11. 2026-06-19 19:26 UTCEPSS rescore
  12. 2026-06-19 19:26 UTCEPSS rescore
  13. 2026-06-18 17:52 UTCEPSS rescore
  14. 2026-06-18 17:52 UTCEPSS rescore
  15. 2026-06-17 17:53 UTCEPSS rescore
  16. 2026-06-16 17:53 UTCEPSS rescore
  17. 2026-06-15 17:49 UTCEPSS rescore
  18. 2026-06-15 17:49 UTCEPSS rescore
  19. 2026-06-14 23:18 UTCEPSS rescore
  20. 2026-06-14 21:38 UTCEG score recompute
  21. 2026-06-14 21:38 UTCVendor advisory
  22. 2026-06-14 21:38 UTCGHSA enrichment
  23. 2026-06-13 23:00 UTCEPSS rescore
  24. 2026-06-12 23:12 UTCEPSS rescore
  25. 2026-06-12 23:12 UTCEPSS rescore
  26. 2026-06-11 19:34 UTCEG score recompute
  27. 2026-06-11 19:34 UTCVendor advisory
  28. 2026-06-11 19:34 UTCGHSA enrichment
  29. 2026-06-11 14:00 UTCEPSS rescore
  30. 2026-06-10 22:19 UTCEPSS rescore
  31. 2026-06-10 13:28 UTCEG score recompute
  32. 2026-06-10 13:28 UTCVendor advisory
  33. 2026-06-10 13:28 UTCGHSA enrichment
  34. 2026-06-10 13:22 UTCEPSS rescore
  35. 2026-06-10 00:43 UTCEG score recompute
  36. 2026-06-10 00:43 UTCVendor advisory
  37. 2026-06-10 00:43 UTCGHSA enrichment
  38. 2026-06-09 11:06 UTCEG score recompute
  39. 2026-06-09 11:06 UTCVendor advisory
  40. 2026-06-09 11:06 UTCGHSA enrichment
  41. 2026-06-08 14:17 UTCEPSS rescore
  42. 2026-06-08 14:17 UTCEPSS rescore
  43. 2026-06-08 07:53 UTCEG score recompute
  44. 2026-06-08 07:53 UTCVendor advisory
  45. 2026-06-08 07:53 UTCGHSA enrichment
  46. 2026-06-07 19:09 UTCEG score recompute
  47. 2026-06-07 19:09 UTCVendor advisory
  48. 2026-06-07 19:09 UTCGHSA enrichment
  49. 2026-06-07 15:25 UTCEPSS rescore
  50. 2026-06-07 15:25 UTCEPSS rescore
  51. 2026-06-07 06:25 UTCEG score recompute
  52. 2026-06-07 06:25 UTCVendor advisory
  53. 2026-06-07 06:25 UTCGHSA enrichment
  54. 2026-06-06 13:47 UTCEPSS rescore
  55. 2026-06-06 13:47 UTCEPSS rescore
  56. 2026-06-05 22:47 UTCEPSS rescore
  57. 2026-06-05 06:10 UTCEPSS rescore
  58. 2026-06-05 06:10 UTCEPSS rescore
  59. 2026-06-04 13:12 UTCEPSS rescore
  60. 2026-06-04 13:12 UTCEPSS rescore
  61. 2026-06-02 20:13 UTCEPSS rescore
  62. 2026-06-02 19:04 UTCEG score recompute
  63. 2026-06-02 19:04 UTCVendor advisory
  64. 2026-06-02 19:04 UTCGHSA enrichment
  65. 2026-06-01 20:59 UTCEG score recompute
  66. 2026-06-01 20:59 UTCVendor advisory
  67. 2026-06-01 20:59 UTCGHSA enrichment
  68. 2026-06-01 13:52 UTCEPSS rescore
  69. 2026-06-01 13:52 UTCEPSS rescore
  70. 2026-05-31 22:30 UTCEPSS rescore
  71. 2026-05-31 22:30 UTCEPSS rescore
  72. 2026-05-31 00:16 UTCEPSS rescore
  73. 2026-05-31 00:16 UTCEPSS rescore
  74. 2026-05-29 13:44 UTCEPSS rescore
  75. 2026-05-29 13:44 UTCEPSS rescore

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-4786?
CVE-2026-4786 is a high vulnerability published on April 13, 2026. Mitgation of CVE-2026-4519 was incomplete. If the URL contained "%action" the mitigation could be bypassed for certain browser types the "webbrowser.open()" API could have commands injected into the underlying shell. See CVE-2026-4519 for details.
When was CVE-2026-4786 disclosed?
CVE-2026-4786 was first published in the National Vulnerability Database on April 13, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-4786 actively exploited?
CVE-2026-4786 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 20.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-4786?
CVE-2026-4786 has a CVSS v3 base score of 7.1 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 7.0.
How do I remediate CVE-2026-4786?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-4786, 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

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