CVE-2026-20896

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 2.8%, top 15% 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, secondary
Elevated
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 3%CVSS: 9.8Exploit: Elevated riskExposed: 0

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

Gitea Docker image versions up to and including 1.26.2 use REVERSE_PROXY_TRUSTED_PROXIES=* by default, allowing any source IP to impersonate a user when reverse-proxy authentication headers such as X-WEBAUTH-USER are enabled.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
75(Attend)
EG Risk 75/100SSVC: Attend

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
Severity98% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
3%
EPSS %ILE
85%
KEV
Not listed

Published

July 3, 2026

Last Modified

July 7, 2026

Advisory Details (4)

Auto-updated Sep 6, 2026
🔬 Proof of concept available. Patch available. Sources: github_pr, github_release, github.
github Patch Available🟡 PoC Available

Gitea Docker image: `REVERSE_PROXY_TRUSTED_PROXIES = *` default lets any source IP impersonate any user via `X-WEBAUTH-USER` · Advisory · go-gitea/gitea · GitHub

https://github.com/go-gitea/gitea/security/advisories/GHSA-f75j-4cw6-rmx4
github_release Patch Available

v1.26.3

Patch available: go-gitea/gitea v1.26.3

https://github.com/go-gitea/gitea/releases/tag/v1.26.3
github_pr

fix: Various security fixes (#38103)

Fix merged in go-gitea/gitea PR #38151 on 2026-06-17 — awaiting tagged release

https://github.com/go-gitea/gitea/pull/38151
generic

Gitea 1.26.3 and 1.26.4 are released | Gitea Blog

https://blog.gitea.com/release-of-1.26.3-and-1.26.4/

Vendor Advisories for CVE-2026-20896(1)

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

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
code.gitea.io/gitea—1.26.3—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 44× 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 109 total refreshes for this CVE.

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

Publicly available exploits

(4 references)

Working exploit code is in the public domain (3 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCXaocZenon/CVE-2026-20896
    First seen Jul 16, 2026

    this is a modified POC of rz1027 for CVE-2026-20896

    Open source ↗
  • GitHub PoCszybnev/cve-2026-20896-gitea-poc
    First seen Jul 7, 2026

    CVE-2026-20896 Gitea Docker X-WEBAUTH-USER auth bypass checker

    Open source ↗
  • GitHub PoCrz1027/CVE-2026-20896
    First seen Jul 5, 2026

    Public PoC and detector for CVE-2026-20896 ("Gitea Docker: One Header, Any User")

    Open source ↗
  • Nucleihttp/cves/2026/CVE-2026-20896.yaml
    First seen Jan 1, 2026

    Gitea Docker Image <= 1.26.2 - Reverse Proxy Header Authentication Bypass

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-20896?
CVE-2026-20896 is a critical vulnerability published on July 3, 2026. Gitea Docker image versions up to and including 1.26.2 use REVERSEPROXYTRUSTED_PROXIES=* by default, allowing any source IP to impersonate a user when reverse-proxy authentication headers such as X-WEBAUTH-USER are enabled.
When was CVE-2026-20896 disclosed?
CVE-2026-20896 was first published in the National Vulnerability Database on July 3, 2026, with the most recent update on July 7, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-20896 actively exploited?
CVE-2026-20896 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3% probability of exploitation in the next 30 days, which ranks it in the top 14.6% of all scored CVEs.
What is the CVSS score of CVE-2026-20896?
CVE-2026-20896 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-20896?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-20896, 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-2026-20896

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