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: 31.8%, top 2% 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: 32%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
32%
EPSS %ILE
98%
KEV
Not listed

Published

July 3, 2026

Last Modified

July 7, 2026

Advisory Details (4)

Auto-updated Jul 26, 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 14× in last 7d / 43× 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. 2026-07-26 16:47 UTCEG score recompute
  2. 2026-07-26 14:54 UTCEPSS rescore
  3. 2026-07-26 14:54 UTCEPSS rescore
  4. 2026-07-26 12:55 UTCEG score recompute
  5. 2026-07-25 14:17 UTCEPSS rescore
  6. 2026-07-25 14:17 UTCEPSS rescore
  7. 2026-07-24 14:17 UTCEPSS rescore
  8. 2026-07-23 14:18 UTCEPSS rescore
  9. 2026-07-23 14:18 UTCEPSS rescore
  10. 2026-07-23 03:06 UTCEG score recompute
  11. 2026-07-22 14:08 UTCEPSS rescore
  12. 2026-07-21 15:24 UTCEPSS rescore
  13. 2026-07-21 15:24 UTCEPSS rescore
  14. 2026-07-20 17:08 UTCEPSS rescore
  15. 2026-07-19 14:31 UTCEPSS rescore
  16. 2026-07-19 14:31 UTCEPSS rescore
  17. 2026-07-19 02:29 UTCEPSS rescore
  18. 2026-07-19 02:28 UTCEPSS rescore
  19. 2026-07-18 10:04 UTCEPSS rescore
  20. 2026-07-18 10:04 UTCEPSS rescore
  21. 2026-07-16 17:03 UTCEPSS rescore
  22. 2026-07-16 17:03 UTCEPSS rescore
  23. 2026-07-15 16:57 UTCEPSS rescore
  24. 2026-07-15 16:57 UTCEPSS rescore
  25. 2026-07-15 02:00 UTCEPSS rescore
Show 18 more
  1. 2026-07-15 02:00 UTCEPSS rescore
  2. 2026-07-13 22:30 UTCEPSS rescore
  3. 2026-07-13 06:13 UTCEPSS rescore
  4. 2026-07-13 06:13 UTCEPSS rescore
  5. 2026-07-12 05:46 UTCEPSS rescore
  6. 2026-07-12 05:46 UTCEPSS rescore
  7. 2026-07-11 08:27 UTCEPSS rescore
  8. 2026-07-09 19:10 UTCEPSS rescore
  9. 2026-07-08 15:15 UTCEPSS rescore
  10. 2026-07-08 15:15 UTCEPSS rescore
  11. 2026-07-07 13:46 UTCEPSS rescore
  12. 2026-07-06 16:27 UTCEPSS rescore
  13. 2026-07-06 16:27 UTCEPSS rescore
  14. 2026-07-06 02:23 UTCEPSS rescore
  15. 2026-07-06 02:23 UTCEPSS rescore
  16. 2026-07-05 02:30 UTCEPSS rescore
  17. 2026-07-03 22:30 UTCEG score recompute
  18. 2026-07-03 22:27 UTCNVD updatefirst tracked

Publicly available exploits

(3 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 ↗

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 32% probability of exploitation in the next 30 days, which ranks it in the top 1.9% 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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