{"id":"CVE-2026-47122","aliases":["EUVD-2026-46275","GHSA-g3hp-f6mg-559v"],"status":"published","title":"Sparkle's AppInstaller post-stage-1 XPC listener accepts unvalidated connections, allowing spoofed appcast item data injection","description":"Sparkle is a software update framework for macOS. In versions up to and including 2.9.1, `Autoupdate/AppInstaller.m`'s `shouldAcceptNewConnection:` only enforces `SUCodeSigningVerifier validateConnection:` before stage 1 completes. After `_performedStage1Installation = YES`, new connections to the registered Mach service `\u003cbundleId\u003e-spki` are accepted from any local process without team-ID or code-signing checks. As of time of publication, no known patched versions are available.","severity":{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00105,"percentile":0.01092,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-306","CWE-441"],"published":"2026-05-29T19:47:19Z","modified":"2026-10-28T02:30:51Z","affected":[{"source":"ghsa","ecosystem":"SwiftURL","package":"github.com/sparkle-project/Sparkle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"2.9.1"}]}]},{"source":"osv","ecosystem":"SwiftURL","package":"github.com/sparkle-project/Sparkle","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"last_affected":"2.9.1"}]}]}],"products":[{"vendor":"sparkle project","product":"sparkle"},{"vendor":"sparkle-project","product":"sparkle"}],"references":[{"url":"https://github.com/sparkle-project/Sparkle/security/advisories/GHSA-g3hp-f6mg-559v","tags":["x_refsource_CONFIRM","Vendor Advisory","Mitigation","advisory","web"]},{"url":"https://github.com/advisories/GHSA-g3hp-f6mg-559v"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47122.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-47122","tags":["advisory"]},{"url":"https://github.com/sparkle-project/Sparkle","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-47122","title":"Sparkle's AppInstaller post-stage-1 XPC listener accepts unvalidated connections, allowing spoofed appcast item data injection","description":"Sparkle is a software update framework for macOS. In versions up to and including 2.9.1, `Autoupdate/AppInstaller.m`'s `shouldAcceptNewConnection:` only enforces `SUCodeSigningVerifier validateConnection:` before stage 1 completes. After `_performedStage1Installation = YES`, new connections to the registered Mach service `\u003cbundleId\u003e-spki` are accepted from any local process without team-ID or code-signing checks. As of time of publication, no known patched versions are available.","status":"published","published":"2026-07-21T13:57:59.824Z","modified":"2026-07-21T14:55:16.991Z","cvss":[{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-306","CWE-441"],"updated_at":"2026-11-02T13:36:40.478484Z"}],"euvd":[{"id":"EUVD-2026-46275","description":"Sparkle is a software update framework for macOS. In versions up to and including 2.9.1, `Autoupdate/AppInstaller.m`'s `shouldAcceptNewConnection:` only enforces `SUCodeSigningVerifier validateConnection:` before stage 1 completes. After `_performedStage1Installation = YES`, new connections to the registered Mach service `\u003cbundleId\u003e-spki` are accepted from any local process without team-ID or code-signing checks. As of time of publication, no known patched versions are available.","status":"published","published":"2026-07-21T13:57:59Z","modified":"2026-07-21T14:55:16Z","cvss":[{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L","level":"medium"}],"updated_at":"2026-11-02T18:19:47.436242Z"}],"ghsa":[{"id":"GHSA-g3hp-f6mg-559v","title":"Sparkle's AppInstaller post-stage-1 XPC listener accepts unvalidated connections, allowing spoofed appcast item data injection","description":"## Summary\n\nAppInstaller post-stage-1 XPC listener accepts unvalidated connections, allowing spoofed appcast item data injection.\n\n## Details\n\n`Autoupdate/AppInstaller.m`'s `shouldAcceptNewConnection:` only enforces `SUCodeSigningVerifier validateConnection:` before stage 1 completes. After `_performedStage1Installation = YES`, new connections to the registered Mach service `\u003cbundleId\u003e-spki` are accepted from any local process without team-ID or code-signing checks.\n\nThe following chain of events enables an attacker to inject a spoofed `SPUSentUpdateAppcastItemData` payload:\n\n1. Installer finishes unarchiving the update successfully (`_willCompleteInstallation` is set).\n2. The app responsible for updating the bundle crashes or is forcefully quit before it has a chance to send `SPUSentUpdateAppcastItemData` to the installer. There is no user interaction between the prior step and this one, so the timing window is tight.\n3. After stage 1 of the installer is performed (`_performedStage1Installation = YES`), but before final installation completes (since all services are cleaned up by then), an attacker process connects to the `\u003cbundleId\u003e-spki` Mach service - no code-signing validation is enforced - and sends a spoofed `SPUSentUpdateAppcastItemData` message containing an attacker-crafted `SUAppcastItem`.\n4. A Sparkle-aware app that checks for updates on the bundle being updated launches before installation completes. The progress agent re-broadcasts the spoofed `SUAppcastItem` on its `\u003cbundleId\u003e-spks` status service, and the launching app displays attacker-controlled release notes (name, version, critical flag).\n\nNote: Sparkle can be used to update other app bundles, so the \"app doing the updating\" and the \"app being updated\" are not necessarily the same bundle.\n\nIn the system-domain case (`SPUUsesSystemDomainForBundlePath = true`), the AppInstaller runs as root via `SMJobSubmit` to `kSMDomainSystemLaunchd`, and the Mach service is reachable by any local user process.\n\nAffected versions: 2.x branch including 2.9.1.\n\n## Impact\n\nA local user-level process can inject a forged `SUAppcastItem` (arbitrary name, version, critical flag) into the progress agent's status broadcast. Other Sparkle-aware clients on the system will display attacker-controlled release notes as authoritative installation state.\n\nThe integrity of the installed code is **not** affected - the bundle moved into place is the legitimate, signature-validated update from stage 1. The impact is limited to UI spoofing of installation metadata.\n\n## Remediation\n\nEnforce `SUCodeSigningVerifier validateConnection:` on all new connections regardless of installation stage, or disallow `SPUSentUpdateAppcastItemData` after the active connection invalidates.","status":"published","published":"2026-05-29T19:47:19Z","modified":"2026-05-29T19:47:20Z","cvss":[{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L","level":"medium"}],"cwes":["CWE-306","CWE-441"],"updated_at":"2026-11-02T14:40:14.666177Z"}],"nvd":[{"id":"CVE-2026-47122","description":"Sparkle is a software update framework for macOS. In versions up to and including 2.9.1, `Autoupdate/AppInstaller.m`'s `shouldAcceptNewConnection:` only enforces `SUCodeSigningVerifier validateConnection:` before stage 1 completes. After `_performedStage1Installation = YES`, new connections to the registered Mach service `\u003cbundleId\u003e-spki` are accepted from any local process without team-ID or code-signing checks. As of time of publication, no known patched versions are available.","status":"published","published":"2026-07-21T15:16:35.327Z","modified":"2026-10-24T20:10:00.137Z","cvss":[{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-306","CWE-441"],"updated_at":"2026-11-02T14:12:31.024898Z"}],"osv":[{"id":"CVE-2026-47122","title":"Sparkle's AppInstaller post-stage-1 XPC listener accepts unvalidated connections, allowing spoofed appcast item data injection","description":"Sparkle is a software update framework for macOS. In versions up to and including 2.9.1, `Autoupdate/AppInstaller.m`'s `shouldAcceptNewConnection:` only enforces `SUCodeSigningVerifier validateConnection:` before stage 1 completes. After `_performedStage1Installation = YES`, new connections to the registered Mach service `\u003cbundleId\u003e-spki` are accepted from any local process without team-ID or code-signing checks. As of time of publication, no known patched versions are available.","status":"published","published":"2026-07-21T13:57:59.824Z","modified":"2026-10-28T02:30:51.911458514Z","cvss":[{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L","level":"medium"}],"cwes":["CWE-306","CWE-441"],"updated_at":"2026-11-02T15:45:06.231145Z"},{"id":"GHSA-g3hp-f6mg-559v","title":"Sparkle's AppInstaller post-stage-1 XPC listener accepts unvalidated connections, allowing spoofed appcast item data injection","description":"## Summary\n\nAppInstaller post-stage-1 XPC listener accepts unvalidated connections, allowing spoofed appcast item data injection.\n\n## Details\n\n`Autoupdate/AppInstaller.m`'s `shouldAcceptNewConnection:` only enforces `SUCodeSigningVerifier validateConnection:` before stage 1 completes. After `_performedStage1Installation = YES`, new connections to the registered Mach service `\u003cbundleId\u003e-spki` are accepted from any local process without team-ID or code-signing checks.\n\nThe following chain of events enables an attacker to inject a spoofed `SPUSentUpdateAppcastItemData` payload:\n\n1. Installer finishes unarchiving the update successfully (`_willCompleteInstallation` is set).\n2. The app responsible for updating the bundle crashes or is forcefully quit before it has a chance to send `SPUSentUpdateAppcastItemData` to the installer. There is no user interaction between the prior step and this one, so the timing window is tight.\n3. After stage 1 of the installer is performed (`_performedStage1Installation = YES`), but before final installation completes (since all services are cleaned up by then), an attacker process connects to the `\u003cbundleId\u003e-spki` Mach service - no code-signing validation is enforced - and sends a spoofed `SPUSentUpdateAppcastItemData` message containing an attacker-crafted `SUAppcastItem`.\n4. A Sparkle-aware app that checks for updates on the bundle being updated launches before installation completes. The progress agent re-broadcasts the spoofed `SUAppcastItem` on its `\u003cbundleId\u003e-spks` status service, and the launching app displays attacker-controlled release notes (name, version, critical flag).\n\nNote: Sparkle can be used to update other app bundles, so the \"app doing the updating\" and the \"app being updated\" are not necessarily the same bundle.\n\nIn the system-domain case (`SPUUsesSystemDomainForBundlePath = true`), the AppInstaller runs as root via `SMJobSubmit` to `kSMDomainSystemLaunchd`, and the Mach service is reachable by any local user process.\n\nAffected versions: 2.x branch including 2.9.1.\n\n## Impact\n\nA local user-level process can inject a forged `SUAppcastItem` (arbitrary name, version, critical flag) into the progress agent's status broadcast. Other Sparkle-aware clients on the system will display attacker-controlled release notes as authoritative installation state.\n\nThe integrity of the installed code is **not** affected - the bundle moved into place is the legitimate, signature-validated update from stage 1. The impact is limited to UI spoofing of installation metadata.\n\n## Remediation\n\nEnforce `SUCodeSigningVerifier validateConnection:` on all new connections regardless of installation stage, or disallow `SPUSentUpdateAppcastItemData` after the active connection invalidates.","status":"published","published":"2026-05-29T19:47:19Z","modified":"2026-09-10T03:50:46.751806526Z","cvss":[{"version":"3.1","score":4.2,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L","level":"medium"}],"cwes":["CWE-306","CWE-441"],"updated_at":"2026-11-02T15:46:47.119724Z"}]}}