CVE-2026-58438 — gitea.dev
HIGHCVE-2026-58438 is a high-severity (CVSS 7.5) CWE-862 vulnerability in gitea.dev. A fix is available for gitea.dev — see the affected versions and patch details below.
Cross-repository IDOR in issue-dependency removal lets an attacker tamper with and comment on private repos they cannot access
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-58438.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-58438 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 380,526 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
gitea.devReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Details
RemoveDependency in routers/web/repo/issue_dependency.go takes a removeDependencyID form parameter identifying the other issue by its global numeric ID, and fetches it with issues_model.GetIssueByID(ctx, depID) - no repository or permission check at all. It then calls issues_model.RemoveIssueDependency(ctx, ctx.Doer, issue, dep, depType) (models/issues/dependency.go), which deletes the dependency join row and then writes a comment referencing the removal, attributed to the calling user, onto the dependency record.
The sibling function in the very same file, AddDependency, does this correctly when the two issues are in different repos (which ALLOW_CROSS_REPOSITORY_DEPENDENCIES, on by default, permits):
if issue.RepoID != dep.RepoID {
if !setting.Service.AllowCrossRepositoryDependencies { ... }
depRepoPerm, err := access_model.GetDoerRepoPermission(ctx, dep.Repo, ctx.Doer)
if !depRepoPerm.CanReadIssuesOrPulls(dep.IsPull) {
return // you can't see this dependency
}
}
RemoveDependency has no equivalent block at all - it goes straight from resolving dep by ID to deleting the link, regardless of which repo dep lives in or whether the caller can see it. I confirmed this same code is present in the current latest release, v1.26.4.
PoC
Prerequisites: an account with write access to issues on some repo ownerA/repoA, and the global numeric issue ID of an issue in a private repo repoB that is (or was) legitimately dependency-linked to one of the attacker's issues in repoA (cross-repo dependencies are commonly used between related public/private repos, and ALLOW_CROSS_REPOSITORY_DEPENDENCIES defaults to enabled).
curl -s -b "gitea_session=$ATTACKER_SESSION_COOKIE" -X POST \
--data-urlencode "removeDependencyID=<repoB_issue_global_id>" \
--data-urlencode "dependencyType=blockedBy" \
"https://TARGET_HOST/ownerA/repoA/issues/N/dependency/delete"
# Expected: the dependency link is deleted and a "removed dependency" comment
# authored by the attacker is added to the repoB issue, even though the
# attacker has no read access to repoB.
Impact
This is a cross-repository IDOR / broken access control issue. An attacker can tamper with issue-tracking state (dependency relationships) and inject an attacker-authored comment into a private repository they cannot otherwise read or write to, crossing a trust boundary the "add" path explicitly enforces. Impact is bounded - it requires an existing dependency link and discloses no repository content - but it is a genuine unauthorized-write primitive across a private-repo boundary.
Fix
Add the same cross-repo permission check used in AddDependency (access_model.GetDoerRepoPermission(ctx, dep.Repo, ctx.Doer).CanReadIssuesOrPulls(dep.IsPull)) to RemoveDependency before allowing the deletion to proceed when issue.RepoID != dep.RepoID.
If possible, please apply for a CVE number when publishing. I would greatly appreciate it.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | gitea.dev | all versions | 1.27.0go get gitea.dev@v1.27.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for gitea.dev, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update gitea.dev to 1.27.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-58438 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
A flaw was found in Gitea's issue-dependency removal logic. Due to insufficient authorization checks, a remote user with issue-write access in one repository can manipulate dependency relations pointing to an issue in a separate, restricted private repository. An attacker can exploit this IDOR flaw by targeting known…
To mitigate this issue, restrict write access to repository issues to trusted users, or temporarily disable issue tracking on affected repositories until a patch is applied.Source: Red Hat security advisory for CVE-2026-58438 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2026-58438 in your dependencies?
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