CVE-2026-20896

CRITICALPre-NVD 9.89.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This critical-severity CVE scores 9.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 2.8% (86th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Elevated

Also known asEUVD-2026-41614 (ENISA EUVD) · GHSA-f75j-4cw6-rmx4 (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • Public exploit or proof-of-concept code is available
CISA-KEV: Not listedEPSS PROB: 2.8%CVSS: 9.8Exploit: Public PoCExposed services: Not assessed

A fix is available — apply it.

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
9.8CRITICALmedium confidence
EG Risk
75
EG Risk 75/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
2.8%
EPSS %ILE
86th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
2.8% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-26). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track* at medium mission impactTrack at low, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

July 3, 2026

Last Modified

October 25, 2026

Advisory Details (4)

Auto-updated Oct 26, 2026
🔬 Proof of concept available. Patch available. Sources: github_pr, github_release, github.
GitHub advisoryMentions a patch (unverified)🟡 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 pull request

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
Web page

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 rangeFix by version rangeDependents
code.gitea.io/gitea—
  • every version up to 1.26.3: fixed in 1.26.3
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 13× in last 7d / 45× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 99 of 168 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 69 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-27 16:31 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  2. 2026-10-26 19:09 UTCEG score recompute
  3. 2026-10-26 16:31 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  4. 2026-10-25 16:32 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  5. 2026-10-25 14:41 UTCEG score recompute
  6. 2026-10-24 16:32 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  7. 2026-10-24 12:42 UTCEG score recompute
  8. 2026-10-23 16:31 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  9. 2026-10-23 10:42 UTCEG score recompute
  10. 2026-10-22 16:34 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  11. 2026-10-22 08:42 UTCEG score recompute
  12. 2026-10-21 16:32 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  13. 2026-10-21 06:43 UTCEG score recompute
  14. 2026-10-20 16:32 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  15. 2026-10-20 04:44 UTCEG score recompute
  16. 2026-10-19 16:31 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  17. 2026-10-19 02:46 UTCEG score recompute
  18. 2026-10-18 16:31 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  19. 2026-10-18 03:56 UTCEG score recompute
  20. 2026-10-18 00:48 UTCEG score recompute
  21. 2026-10-17 16:33 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  22. 2026-10-16 22:48 UTCEG score recompute
  23. 2026-10-16 16:41 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  24. 2026-10-15 19:45 UTCEG score recompute
  25. 2026-10-15 16:31 UTCEPSS rescoreEPSS 2.8% · 85th percentile
Show 74 more
  1. 2026-10-14 16:32 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  2. 2026-10-14 13:22 UTCEG score recompute
  3. 2026-10-13 16:33 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  4. 2026-10-13 11:22 UTCEG score recompute
  5. 2026-10-12 16:33 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  6. 2026-10-12 16:23 UTCEG score recompute
  7. 2026-10-11 20:05 UTCEG score recompute
  8. 2026-10-11 17:18 UTCEG score recompute
  9. 2026-10-11 14:50 UTCEG score recompute
  10. 2026-10-11 13:48 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  11. 2026-10-10 19:59 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  12. 2026-10-09 20:06 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  13. 2026-10-08 17:11 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  14. 2026-10-07 23:47 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  15. 2026-10-06 15:17 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  16. 2026-10-05 17:42 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  17. 2026-10-01 19:49 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  18. 2026-09-30 15:03 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  19. 2026-09-29 15:21 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  20. 2026-09-28 13:51 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  21. 2026-09-27 13:47 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  22. 2026-09-26 15:58 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  23. 2026-09-26 00:26 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  24. 2026-09-24 14:03 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  25. 2026-09-23 06:34 UTCEG score recompute
  26. 2026-09-20 20:15 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  27. 2026-09-18 19:27 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  28. 2026-09-18 06:11 UTCEG score recompute
  29. 2026-09-16 14:07 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  30. 2026-09-16 05:15 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  31. 2026-09-13 16:53 UTCEG score recompute
  32. 2026-09-13 16:47 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  33. 2026-09-13 08:55 UTCEG score recompute
  34. 2026-09-12 15:01 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  35. 2026-09-12 14:01 UTCEG score recompute
  36. 2026-09-11 14:52 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  37. 2026-09-10 09:34 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  38. 2026-09-08 22:00 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  39. 2026-09-07 16:01 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  40. 2026-09-06 14:17 UTCEG score recompute
  41. 2026-09-06 13:47 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  42. 2026-09-05 23:41 UTCEG score recompute
  43. 2026-09-04 05:06 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  44. 2026-09-02 14:11 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  45. 2026-09-01 13:53 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  46. 2026-09-01 04:39 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  47. 2026-08-30 20:43 UTCEG score recompute
  48. 2026-08-30 19:17 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  49. 2026-08-30 11:18 UTCEG score recompute
  50. 2026-08-30 01:22 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  51. 2026-08-28 21:41 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  52. 2026-08-27 22:12 UTCEG score recompute
  53. 2026-08-27 14:25 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  54. 2026-08-27 02:59 UTCEG score recompute
  55. 2026-08-26 14:46 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  56. 2026-08-26 14:32 UTCEG score recompute
  57. 2026-08-25 13:48 UTCEPSS rescoreEPSS 2.8% · 85th percentile
  58. 2026-08-24 20:52 UTCEG score recompute
  59. 2026-08-24 10:12 UTCEG score recompute
  60. 2026-08-22 00:58 UTCEG score recompute
  61. 2026-08-21 23:49 UTCEPSS rescoreEPSS 62% · 99th percentile
  62. 2026-08-21 04:25 UTCEG score recompute
  63. 2026-08-20 23:36 UTCEG score recompute
  64. 2026-08-20 22:55 UTCEPSS rescoreEPSS 62% · 99th percentile
  65. 2026-08-20 03:42 UTCEG score recompute
  66. 2026-08-19 17:03 UTCEPSS rescoreEPSS 32% · 98th percentile
  67. 2026-08-18 20:52 UTCEG score recompute
  68. 2026-08-18 13:48 UTCEPSS rescoreEPSS 32% · 98th percentile
  69. 2026-08-17 15:02 UTCEG score recompute
  70. 2026-08-17 13:47 UTCEPSS rescoreEPSS 32% · 98th percentile
  71. 2026-08-16 19:42 UTCEG score recompute
  72. 2026-08-16 14:56 UTCEPSS rescoreEPSS 32% · 98th percentile
  73. 2026-08-16 03:16 UTCEG score recompute
  74. 2026-08-16 02:14 UTCEPSS rescoreEPSS 32% · 98th percentile

Publicly available exploits

(4 references)

Public exploit code is referenced for this CVE (3 GitHub PoCs), as is 1 Nuclei detection template. A detection template checks whether a system is affected; it is not necessarily exploit code. Defenders should treat patch urgency accordingly.

  • Nucleihttp/cves/2026/CVE-2026-20896.yaml
    Published Aug 19, 2026

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

    Open source ↗
  • GitHub PoCXaocZenon/CVE-2026-20896
    Published Jul 16, 2026

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

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

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

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

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

    Open source ↗

Frequently asked(5)

What is CVE-2026-20896?
CVE-2026-20896 is a critical-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-20896 published?
The CVE record for CVE-2026-20896 was published on July 3, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 25, 2026; the record at its source may have been updated since.
Is CVE-2026-20896 actively exploited?
CVE-2026-20896 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.8% probability of exploitation in the next 30 days (86th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-20896?
CVE-2026-20896 has a CVSS base score of 9.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-20896?
A fix for CVE-2026-20896 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-20896 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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