How should we interpret CVSS severity scores?

CVSS estimates technical severity, but it does not automatically equal business risk. Prioritize using context like internet exposure, asset criticality, known exploitation, and whether compensating controls exist. A Medium CVSS on an exposed production system can be more urgent than a Critical on an isolated non-production host.

Vulnerability Database

Q: What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

Q: What's the difference between a vulnerability, an exploit, and a zero-day?

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. Risk increases sharply when exploitation becomes reliable or widespread.

Q: Why do vulnerabilities keep reappearing in our environment?

Recurring findings usually come from incomplete asset discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host.

Q: How do we prioritize remediation without burning out the team?

Use a repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress so remediation is steady, not reactive.

Q: How can SynScan help reduce vulnerability risk over time?

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.

362,873

Total vulnerabilities in the database

CVE-2026-58416 — gitea.dev

Improper Handling of Insufficient Permissions or Privileges

Summary

GetActionsUserRepoPermission (models/perm/access/repo_permission.go) decides whether an Actions task token may access a target repo. Its cross-repo branches each enforce a fork-PR discriminator — except the collaborative-owner branch, which is missing the !task.IsForkPullRequest guard that its sibling has. As a result, when a private repo B lists owner A as a collaborative owner, an attacker-controlled fork pull-request workflow whose base repo is owned by A is granted code-read on B — i.e. the fork's YAML can clone a third private repository it has no rights to.

Details

// models/perm/access/repo_permission.go (v1.26.2), in GetActionsUserRepoPermission
if checkSameOwnerCrossRepoAccess(ctx, taskRepo, repo, task.IsForkPullRequest) { // passes isForkPR -&gt; denies forks
    return maxPerm, nil
}
...
if taskRepo.IsPrivate {                                   // &lt;-- NO IsForkPullRequest check here
    actionsUnit := repo.MustGetUnit(ctx, unit.TypeActions)
    if actionsUnit.ActionsConfig().IsCollaborativeOwner(taskRepo.OwnerID) {
        return maxPerm, nil                              // grants code-read to target repo B
    }
}

The sibling same-owner path correctly denies fork PRs:

func checkSameOwnerCrossRepoAccess(ctx, taskRepo, targetRepo, isForkPR bool) bool {
    if isForkPR {
        return false // Fork PRs are never allowed cross-repo access to other private repositories.
    }
    ...
}

taskRepo = the repo whose workflow is running (the PR's base repo A); repo = the target being cloned (B). IsCollaborativeOwner(taskRepo.OwnerID) asks "does target B's Actions config trust A's owner for cross-repo read?" When B trusts ownerA, the branch returns maxPerm (code-read) even when task.IsForkPullRequest is true — i.e. when the executing YAML is the fork's, not A's.

Every sibling enforces the fork-PR discriminator; except for this branch: checkSameOwnerCrossRepoAccess denies forks; ComputeTaskTokenPermissions (models/actions/token_permissions.go) only clamps the token ceiling to read-only for fork/cross-repo (its own comment notes the access decision is in GetActionsUserRepoPermission, so it does not neutralize the gap — it just makes the leak read-only); secrets (models/secret/secret.go) and the approval gate (services/actions/notifier_helper.go) both correctly key on IsForkPullRequest.

Reachability — the runner clones target repo B over git-HTTP with the task token: routers/web/repo/githttp.go → GetDoerRepoPermission(ctx, repoB, ActionsUser) → GetActionsUserRepoPermission(ctx, repoB, actionsUser, taskID) with IsForkPullRequest == true → collaborative-owner branch returns code-read → p.CanAccess(Read, code) passes → private clone of B succeeds. (CheckRepoScopedToken in githttp is a no-op for the Actions token.)

PoC

Setup: private base repo A (usera/repoA), private third repo B (userb/repoB) with a planted SECRET.txt, B's Actions config trusting usera as a collaborative owner, and a genuine running fork-PR task token (token_hash computed with Gitea's own HashToken) presented as HTTP Basic. Requesting GET /userb/repoB.git/info/refs?service=git-upload-pack:

| Condition (same fork-PR token) | HTTP | Meaning | |---|---|---| | anonymous (no token) | 401 | auth required | | token, A public, B trusts A | 404 | branch gated on taskRepo.IsPrivate ⇒ A public skips it | | token, A private, B has no collab-owner config | 404 | no trust ⇒ denied | | token, A private, B trusts A (collab-owner) | 200 | git clone of private B succeeds | | config removed / restored | 404 / 200 | deterministic |

In the 200 case, git clone of private repo B succeeded and yielded its SECRET.txt — the full source of a third private repo the fork-PR author has no rights to.

Impact

Read-only confidentiality breach: discloses the full source of a third private repository (B) to an untrusted external fork-PR author. Read-only, not write/RCE.

Preconditions (honest):

B is deliberately configured with a collaborative owner — but that is exactly the feature's intended use, so realistic for any deployment using it.
The fork PR's base repo A is itself private (the branch is gated on taskRepo.IsPrivate). Forking a private A already requires read on A, so this is a normal internal-contributor situation, not a weakening — the escalation is "read A (granted) → read a different private repo B (never granted)."
The fork-PR workflow must actually run — most realistically via an attacker who had one earlier PR approved (the "approved before" path in ifNeedApproval), after which fork PRs auto-run.

Suggested remediation

Add the same fork-PR guard the sibling path has (one line):

if taskRepo.IsPrivate &amp;&amp; !task.IsForkPullRequest {
    actionsUnit := repo.MustGetUnit(ctx, unit.TypeActions)
    if actionsUnit.ActionsConfig().IsCollaborativeOwner(taskRepo.OwnerID) {
        return maxPerm, nil
    }
}

This flips Vuln_ForkPR_LeaksThirdPrivateRepo to PASS, keeps Control_NonFork_Allowed PASS (legitimate collaborative-owner sharing still works), and leaves the existing TestGetActionsUserRepoPermission suite all green.

Published: Jul 21, 2026
Updated: Jul 22, 2026
CVE: CVE-2026-58416
GHSA: GHSA-fj8v-hjwv-qm88
Severity: Medium
Exploit:
CISA KEV:

CVSS v3:

Severity: Medium
Score: 6.3
AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

CWEs:

Affected Software
References

Software	From	Fixed in
gitea.dev	-	1.27.0

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Frequently Asked Questions

What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.