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Gitea: Token scope bypass on web archive download endpoint

Moderate severity GitHub Reviewed Published Jun 5, 2026 in go-gitea/gitea • Updated Jun 16, 2026

Package

gomod code.gitea.io/gitea (Go)

Affected versions

<= 1.26.1

Patched versions

1.26.2

Description

Summary

PR #37698 added checkDownloadTokenScope to /raw/, /media/, and attachment download web endpoints. The /archive/* endpoint (repo.Download in routers/web/repo/repo.go:372) was not included in the fix. This endpoint accepts OAuth2 tokens via webAuth.AllowOAuth2 (registered at routers/web/web.go:1649-1652) but does not call checkDownloadTokenScope or CheckRepoScopedToken.

A personal access token with any non-repository scope (e.g., read:issue or read:misc) can download full repository archives (zip/tar.gz) of private repositories the token owner has access to.

Impact

Scope escalation: tokens scoped to non-repository categories can access full repository content through the archive download endpoint. Higher impact than endpoints fixed in #37698 because /archive/* serves the entire repository.

Steps to Reproduce

  1. Create a personal access token with ONLY read:misc scope
  2. Access: GET /{owner}/{private-repo}/archive/main.tar.gz
  3. Archive is served (200 OK) instead of being rejected (403 Forbidden)

Compare with fixed endpoints:

  • GET /{owner}/{private-repo}/raw/branch/main/README.md correctly returns 403

Root Cause

Download function in routers/web/repo/repo.go:372 does not call checkDownloadTokenScope. The outer group middleware reqUnitCodeReader checks repository permission but not token scope.

The API equivalent (/api/v1/repos/{owner}/{repo}/archive/*) IS properly scoped via tokenRequiresScopes(AccessTokenScopeCategoryRepository). The git HTTP endpoints are scoped via CheckRepoScopedToken in httpBase.

Suggested Fix

Add checkDownloadTokenScope(ctx) to Download and InitiateDownload in routers/web/repo/repo.go. The function already exists in routers/web/repo/download.go (same package).

Discovery Method

Variant analysis of PR #37698 — reviewed all web routes with webAuth.AllowOAuth2 middleware.

References

@lunny lunny published to go-gitea/gitea Jun 5, 2026
Published to the GitHub Advisory Database Jun 16, 2026
Reviewed Jun 16, 2026
Last updated Jun 16, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required Low
User interaction None
Vulnerable System Impact Metrics
Confidentiality Low
Integrity None
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(7th percentile)

Weaknesses

Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. Learn more on MITRE.

CVE ID

CVE-2026-20706

GHSA ID

GHSA-cr4g-f395-h25h

Source code

Credits

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