Quick answers
- Is CVE-2026-47121 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-47121 being exploited in the wild.
- How severe is CVE-2026-47121?
- Medium severity, with a CVSS score of 6.1, published 21 July 2026.
- Which products and versions are affected?
- Sparkle Project Sparkle < 2.9.2, <= 2.9.1; github.com/sparkle-project/Sparkle (Swift) <= 2.9.1.
- Is there a fix for CVE-2026-47121?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-47121 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-47121?
- Check whether you run Sparkle Project Sparkle or github.com/sparkle-project/Sparkle (Swift) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A path traversal vulnerability exists in Sparkle's `SUBinaryDeltaApply.m` and `SPUSparkleDeltaArchive.m` components. The framework's delta update mechanism fails to recursively validate all path components for symbolic links. An attacker can craft a `.delta` archive that first creates a symlink pointing to a sensitive system directory (e.g., `/Library/LaunchDaemons`) and then extracts a subsequent file using a path that traverses through that symlink. Because `fopen()` resolves intermediate symlinks, the file is written outside the intended destination tree. Exploitation requires the attacker to possess a valid EdDSA signing key to pass signature verification. If the update process is running as root (system-domain installs), this grants arbitrary root-level file write capabilities. The issue is addressed in version 2.9.2.
Affected products
- sparkle-project Sparkle < 2.9.2
Identifiers
- CVE-2026-47121
- GHSA-hg88-v3cw-3qrh
Timeline
- 2026-05-19: advisory: Internal GitHub advisory published
- 2026-07-21: disclosed: NVD publication date