Summary
Gitea: Null Pointer Dereference in AddTime API Causes Authenticated Denial of Service
The AddTime API handler continues execution after an error returned by GetUserByName().
When a repository administrator specifies a non-existent user name, an error response is generated but execution does not stop. Subsequent code dereferences a nil user pointer, resulting in a runtime panic.
Details
Affected endpoint:
POST /api/v1/repos/{owner}/{repo}/issues/{index}/times
Affected file:
routers/api/v1/repo/issue_tracked_time.go
Relevant code:
user, err = user_model.GetUserByName(ctx, form.User)
if err != nil {
ctx.APIErrorInternal(err)
// missing return
}
Execution continues to:
trackedTime, err := issues_model.AddTime(
ctx,
user,
issue,
form.Time,
created,
)
When GetUserByName() fails, user is nil.
The subsequent call dereferences the nil pointer and triggers a runtime panic.
Proof of Concept
Using a repository administrator account:
POST /api/v1/repos/owner/repo/issues/1/times
Content-Type: application/json
{
"time": 3600,
"user_name": "nonexistent_user_xyz"
}
Result:
HTTP 500
runtime error: invalid memory address or nil pointer dereference
The stack trace indicates execution reaches the AddTime code path with a nil user object.
Impact
An authenticated repository administrator can repeatedly trigger server-side panics through the affected endpoint.
Depending on deployment configuration and panic recovery behavior, this may result in request failures, stack trace disclosure, excessive log generation, or degraded service availability.
The application dereferences a null pointer, causing a crash. Typical impact: denial of service via crash.
CVE-2026-55984 has a CVSS score of 2.7 (Low). The vector is network-reachable, high privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.27.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Add a return statement after the error response:
user, err = user_model.GetUserByName(ctx, form.User)
if err != nil {
ctx.APIErrorInternal(err)
return
}
Frequently Asked Questions
- What is CVE-2026-55984? CVE-2026-55984 is a low-severity null pointer dereference vulnerability in code.gitea.io/gitea (go), affecting versions < 1.27.0. It is fixed in 1.27.0. The application dereferences a null pointer, causing a crash.
- How severe is CVE-2026-55984? CVE-2026-55984 has a CVSS score of 2.7 (Low). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of code.gitea.io/gitea are affected by CVE-2026-55984? code.gitea.io/gitea (go) versions < 1.27.0 is affected.
- Is there a fix for CVE-2026-55984? Yes. CVE-2026-55984 is fixed in 1.27.0. Upgrade to this version or later.
- Is CVE-2026-55984 exploitable, and should I be worried? Whether CVE-2026-55984 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-55984 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-55984? Upgrade
code.gitea.io/giteato 1.27.0 or later.