CVE-2026-4296

HIGHNVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-04-22. NVD baseline CVSS 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.8Exploit: None knownExposed: 0

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

An incorrect regular expression vulnerability was identified in GitHub Enterprise Server that allowed an attacker to bypass OAuth redirect URI validation. An attacker with knowledge of a first-party OAuth application's registered callback URL could craft a malicious authorization link that, when clicked by a victim, would redirect the OAuth authorization code to an attacker-controlled domain. This could allow the attacker to gain unauthorized access to the victim's account with the scopes granted to the OAuth application. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.1, 3.19.5, 3.18.8, 3.17.14, 3.16.17, 3.15.21, 3.14.26. This vulnerability was reported via the GitHub Bug Bounty program.

CVSS v3
8.8
EG Score
8.8(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity88% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
24%
KEV
Not listed

Published

April 21, 2026

Last Modified

April 29, 2026

Advisory Details (7)

Auto-updated May 2, 2026
No patch confirmed yet.
generic

Release notes - GitHub Enterprise Server 3.20 Docs

https://docs.github.com/en/[email protected]/admin/release-notes#3.20.1
generic

Release notes - GitHub Enterprise Server 3.19 Docs

https://docs.github.com/en/[email protected]/admin/release-notes#3.19.5
generic

Release notes - GitHub Enterprise Server 3.18 Docs

https://docs.github.com/en/[email protected]/admin/release-notes#3.18.8
generic

Release notes - GitHub Enterprise Server 3.17 Docs

https://docs.github.com/en/[email protected]/admin/release-notes#3.17.14
generic

Release notes - GitHub Enterprise Server 3.16 Docs

https://docs.github.com/en/[email protected]/admin/release-notes#3.16.17
generic

Release notes - GitHub Enterprise Server 3.15 Docs

https://docs.github.com/en/[email protected]/admin/release-notes#3.15.21
generic

Release notes - GitHub Enterprise Server 3.14 Docs

https://docs.github.com/en/[email protected]/admin/release-notes#3.14.26

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 33× 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 112 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-4296?
CVE-2026-4296 is a high vulnerability published on April 21, 2026. An incorrect regular expression vulnerability was identified in GitHub Enterprise Server that allowed an attacker to bypass OAuth redirect URI validation. An attacker with knowledge of a first-party OAuth application's registered callback URL could craft a malicious authorization link that, when…
When was CVE-2026-4296 disclosed?
CVE-2026-4296 was first published in the National Vulnerability Database on April 21, 2026, with the most recent update on April 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-4296 actively exploited?
CVE-2026-4296 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 75.9% of all scored CVEs.
What is the CVSS score of CVE-2026-4296?
CVE-2026-4296 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-4296?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-4296, 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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