{"items":[{"id":"NVI-00016153","kind":"vulnerability","title":"Gitea Actions Artifacts V4 signed URL HMAC ambiguity allows cross-repository artifact read and cross-task upload-state write","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-hg5r-vq93-9fv6","CVE-2026-58426"],"plain_summary":"GitHub lists this reviewed advisory for code.gitea.io/gitea. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-32af36f133dae4585eeaf572d6cb850d"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-07-21T20:36:41.000Z","value":"9.6 critical","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-32af36f133dae4585eeaf572d6cb850d"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-32af36f133dae4585eeaf572d6cb850d","url":"https://github.com/advisories/GHSA-hg5r-vq93-9fv6","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-hg5r-vq93-9fv6","publisher":"GitHub Advisory Database","observed_at":"2026-11-03T22:34:39.734Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-32af36f133dae4585eeaf572d6cb850d"],"technology":"code.gitea.io/gitea","known_exclusions":[],"conditions_summary":"### Summary\n\nGitea Actions Artifacts V4 signed upload/download URLs can be rewritten to access a different running task and repository context while preserving the original HMAC signature. An attacker with permission to run a Gitea Actions job can turn a signed URL for an attacker-controlled artifact into a URL that reads artifacts from another task context, or writes attacker-controlled data into another task's artifact upload staging context, including in a private repository.\n\nThis is one vulnerability with two exploit paths:\n\n- `DownloadArtifact`: cross-task/cross-repository artifact read, giving `C:H`.\n- `UploadArtifact`: cross-task artifact staging write and metadata mutation, giving `I:H`.\n\n### Details\n\nThe root cause is that the V4 artifact signed URL signature is built from raw concatenated fields without delimiters or length-prefixing:\n\n```go\nfunc (r *artifactV4Routes) buildSignature(endpoint, expires, artifactName string, taskID, artifactID int64) []byte {\n        mac := hmac.New(sha256.New, setting.GetGeneralTokenSigningSecret())\n        mac.Write([]byte(endpoint))\n        mac.Write([]byte(expires))\n        mac.Write([]byte(artifactName))\n        _, _ = fmt.Fprint(mac, ","public_affected_ranges":[">= 1.22.0, < 1.26.2"]}],"null_published_at":"2026-11-04T10:04:27.899Z","source_updated_at":"2026-07-21T20:36:41.000Z","source_disclosed_at":"2026-07-21T20:36:38.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-03T22:34:39.734Z"}],"next_cursor":null,"snapshot_revision":"42594"}