CVE-2026-23603Public exploitNetwork attack vector

Blind SSRF via unvalidated OAuth avatar URL

Published Aug 13, 2026 · Updated Aug 14, 2026

SSRF in Gitea 1.26.4 and earlier allows remote authenticated users to send HTTP GET requests to internal services via OAuth2 login. The oauth2UpdateAvatarIfNeed function passes the OIDC picture claim to http.Get without outbound host or IP restrictions. Exploitation requires UPDATE_AVATAR, a configured OAuth2 source, and control of the picture claim; responses are normally blind unless valid image data is stored.

CVSS severity3.1
Low
EPSS probability0.25%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

SSRF in Gitea 1.26.4 and earlier allows remote authenticated users to send HTTP GET requests to internal services via OAuth2 login. The oauth2UpdateAvatarIfNeed function passes the OIDC picture claim to http.Get without outbound host or IP restrictions. Exploitation requires UPDATE_AVATAR, a configured OAuth2 source, and control of the picture claim; responses are normally blind unless valid image data is stored.

The record

CVE
CVE-2026-23603
Published
Aug 13, 2026
Updated
Aug 14, 2026
Vendor
Gitea
Product
Gitea
Classifications
CWE-918, CAPEC-664, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=1.26.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Gitea · Giteaversion=0 <=1.26.4

Published CVSS scores

3.1GitHub Security AdvisoryCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
CAPEC-664Server Side Request Forgery
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo