CVE-2026-55984: Gitea Denial of Service Vulnerability

LOW
Advisory Identifier: GHSA-m932-crvm-gcp5
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CVSS 2.7
CWE-476
Published
Advisory Summary

CVE-2026-55984 is a LOW (CVSS 2.7) denial of service vulnerability (CWE-476: NULL Pointer Dereference) affecting Gitea libraries in the Go ecosystem. The issue involves null pointer dereference in addtime api causes authenticated denial of service. Remediation is available by upgrading affected packages to version 1.27.0.

CVE-2026-55984 at a Glance

CVE Identifier CVE-2026-55984
GHSA Identifier GHSA-m932-crvm-gcp5
Severity LOW
CVSS v3.1 Base Score 2.7
CWE Classification CWE-476: NULL Pointer Dereference
Affected Product Gitea
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 2.7

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required High (PR:H)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability Low (A:L)

How to Fix CVE-2026-55984

To remediate this vulnerability, upgrade all affected Gitea dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

code.gitea.io/gitea fixed: 1.27.0 
Upgrade code.gitea.io/gitea to 1.27.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for code.gitea.io/gitea

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-55984, inspect your project dependencies for Gitea:

inspect dependencies for code.gitea.io/gitea

Analyze the terminal output to locate any version of Gitea in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.27.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-476: NULL Pointer Dereference, where the product dereferences a pointer that it expects to be valid but is null. In Gitea, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary 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: ```http POST /api/v1/repos/{owner}/{repo}/issues/{index}/times ``` Affected file: ```text routers/api/v1/repo/issue_tracked_time.go ``` Relevant code: ```go user, err = user_model.GetUserByName(ctx, form.User) if err != nil { ctx.APIErrorInternal(err) // missing return } ``` Execution continues to: ```go 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: ```http POST /api/v1/repos/owner/repo/issues/1/times Content-Type: application/json { "time": 3600, "user_name": "nonexistent_user_xyz" } ``` Result: ```text 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. ### Suggested Fix Add a return statement after the error response: ```go user, err = user_model.GetUserByName(ctx, form.User) if err != nil { ctx.APIErrorInternal(err) return } ```

CVE-2026-55984 Affected Gitea Versions

1 component(s)
Fixed Versions:
1.27.0
Product / Package Ecosystem Affected Versions Fixed Version
code.gitea.io/gitea
golang/code.gitea.io/gitea
Go
< 1.27.0
1.27.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/go-gitea/gitea/security/advisories/GHSA-m932-crvm-gcp5
Gitea Source Repository REPOSITORY
https://github.com/go-gitea/gitea
Gitea Release RELEASE
https://github.com/go-gitea/gitea/releases/tag/v1.27.0

Frequently Asked Questions

What is CVE-2026-55984?
CVE-2026-55984 is a security vulnerability in Gitea involving Null Pointer Dereference in AddTime API Causes Authenticated Denial of Service under CWE-476: NULL Pointer Dereference.
Which Gitea versions are affected?
Affected versions include releases prior to 1.27.0 across affected packages: code.gitea.io/gitea.
What version fixes CVE-2026-55984?
Upgrading to 1.27.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is code.gitea.io/gitea affected?
Yes, code.gitea.io/gitea is affected in releases prior to 1.27.0. Upgrade your dependency to 1.27.0 or later.
What is the CVSS score of CVE-2026-55984?
CVE-2026-55984 has a CVSS v3.1 base score of 2.7 (LOW) with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L.
What CWE is associated with CVE-2026-55984?
CVE-2026-55984 is classified under CWE-476: NULL Pointer Dereference (The product dereferences a pointer that it expects to be valid but is NULL.).
How can I check Go dependencies for CVE-2026-55984?
Run the dependency tree command: 'inspect dependencies for code.gitea.io/gitea'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-m932-crvm-gcp5",
  "modified" : "2026-07-21T20:59:14Z",
  "published" : "2026-07-21T20:59:14Z",
  "aliases" : [ "CVE-2026-55984" ],
  "summary" : "Gitea: Null Pointer Dereference in AddTime API Causes Authenticated Denial of Service",
  "details" : "### Summary\n\nThe AddTime API handler continues execution after an error returned by `GetUserByName()`.\n\nWhen 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.\n\n### Details\n\nAffected endpoint:\n\n```http\nPOST /api/v1/repos/{owner}/{repo}/issues/{index}/times\n```\n\nAffected file:\n\n```text\nrouters/api/v1/repo/issue_tracked_time.go\n```\n\nRelevant code:\n\n```go\nuser, err = user_model.GetUserByName(ctx, form.User)\nif err != nil {\n    ctx.APIErrorInternal(err)\n    // missing return\n}\n```\n\nExecution continues to:\n\n```go\ntrackedTime, err := issues_model.AddTime(\n    ctx,\n    user,\n    issue,\n    form.Time,\n    created,\n)\n```\n\nWhen `GetUserByName()` fails, `user` is nil.\n\nThe subsequent call dereferences the nil pointer and triggers a runtime panic.\n\n### Proof of Concept\n\nUsing a repository administrator account:\n\n```http\nPOST /api/v1/repos/owner/repo/issues/1/times\nContent-Type: application/json\n\n{\n  \"time\": 3600,\n  \"user_name\": \"nonexistent_user_xyz\"\n}\n```\n\nResult:\n\n```text\nHTTP 500\nruntime error: invalid memory address or nil pointer dereference\n```\n\nThe stack trace indicates execution reaches the AddTime code path with a nil user object.\n\n### Impact\n\nAn authenticated repository administrator can repeatedly trigger server-side panics through the affected endpoint.\n\nDepending on deployment configuration and panic recovery behavior, this may result in request failures, stack trace disclosure, excessive log generation, or degraded service availability.\n\n### Suggested Fix\n\nAdd a return statement after the error response:\n\n```go\nuser, err = user_model.GetUserByName(ctx, form.User)\nif err != nil {\n    ctx.APIErrorInternal(err)\n    return\n}\n```",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "code.gitea.io/gitea"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.27.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/go-gitea/gitea/security/advisories/GHSA-m932-crvm-gcp5"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/go-gitea/gitea"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/go-gitea/gitea/releases/tag/v1.27.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-476" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-21T20:59:14Z",
    "nvd_published_at" : null
  }
}