{"id":"CVE-2026-23950","summary":"node-tar has Race Condition in Path Reservations via Unicode Ligature Collisions on macOS APFS","details":"node-tar,a Tar for Node.js, has a race condition vulnerability in versions up to and including 7.5.3. This is due to an incomplete handling of Unicode path collisions in the `path-reservations` system. On case-insensitive or normalization-insensitive filesystems (such as macOS APFS, In which it has been tested), the library fails to lock colliding paths (e.g., `ß` and `ss`), allowing them to be processed in parallel. This bypasses the library's internal concurrency safeguards and permits Symlink Poisoning attacks via race conditions. The library uses a `PathReservations` system to ensure that metadata checks and file operations for the same path are serialized. This prevents race conditions where one entry might clobber another concurrently. This is a Race Condition which enables Arbitrary File Overwrite. This vulnerability affects users and systems using node-tar on macOS (APFS/HFS+). Because of using `NFD` Unicode normalization (in which `ß` and `ss` are different), conflicting paths do not have their order properly preserved under filesystems that ignore Unicode normalization (e.g., APFS (in which `ß` causes an inode collision with `ss`)). This enables an attacker to circumvent internal parallelization locks (`PathReservations`) using conflicting filenames within a malicious tar archive. The patch in version 7.5.4 updates `path-reservations.js` to use a normalization form that matches the target filesystem's behavior (e.g., `NFKD`), followed by first `toLocaleLowerCase('en')` and then `toLocaleUpperCase('en')`. As a workaround, users who cannot upgrade promptly, and who are programmatically using `node-tar` to extract arbitrary tarball data should filter out all `SymbolicLink` entries (as npm does) to defend against arbitrary file writes via this file system entry name collision issue.","aliases":["GHSA-r6q2-hw4h-h46w"],"modified":"2026-04-02T13:13:30.020811Z","published":"2026-01-20T00:40:48.510Z","related":["CGA-j5r9-cgjp-w62q"],"database_specific":{"cna_assigner":"GitHub_M","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23950.json","cwe_ids":["CWE-176","CWE-352","CWE-367"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23950.json"},{"type":"ADVISORY","url":"https://github.com/isaacs/node-tar/security/advisories/GHSA-r6q2-hw4h-h46w"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23950"},{"type":"FIX","url":"https://github.com/isaacs/node-tar/commit/3b1abfae650056edfabcbe0a0df5954d390521e6"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/isaacs/node-tar","events":[{"introduced":"0"},{"fixed":"911c886bb170a6ee3db05fd3709221752213ec8a"}]}],"versions":["0.1.0","0.1.10","0.1.11","0.1.12","0.1.13","0.1.2","0.1.3","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9","v0.1.14","v0.1.15","v0.1.16","v0.1.17","v0.1.18","v0.1.19","v0.1.20","v1.0.0","v1.0.1","v1.0.2","v1.0.3","v2.0.0","v2.0.1","v2.1.0","v2.1.1","v2.2.1","v2.2.2","v3.0.0","v3.0.1","v3.1.0","v3.1.1","v3.1.10","v3.1.11","v3.1.12","v3.1.13","v3.1.14","v3.1.15","v3.1.2","v3.1.3","v3.1.4","v3.1.5","v3.1.6","v3.1.7","v3.1.8","v3.1.9","v3.2.0","v3.2.1","v3.2.2","v3.2.3","v4.0.0","v4.0.1","v4.0.2","v4.1.0","v4.1.1","v4.1.2","v4.2.0","v4.3.0","v4.3.1","v4.3.2","v4.3.3","v4.4.0","v4.4.1","v4.4.10","v4.4.11","v4.4.12","v4.4.13","v4.4.14","v4.4.15","v4.4.16","v4.4.17","v4.4.18","v4.4.19","v4.4.2","v4.4.3","v4.4.4","v4.4.5","v4.4.6","v4.4.7","v4.4.8","v4.4.9","v5.0.0","v5.0.1","v5.0.10","v5.0.11","v5.0.2","v5.0.3","v5.0.4","v5.0.5","v5.0.6","v5.0.7","v5.0.8","v5.0.9","v6.0.0","v6.0.1","v6.0.2","v6.0.3","v6.0.4","v6.0.5","v6.1.0","v6.1.1","v6.1.10","v6.1.11","v6.1.12","v6.1.13","v6.1.14","v6.1.15","v6.1.2","v6.1.3","v6.1.4","v6.1.5","v6.1.6","v6.1.7","v6.1.8","v6.1.9","v6.2.0","v6.2.1","v7.0.0","v7.0.1","v7.1.0","v7.2.0","v7.3.0","v7.4.0","v7.4.1","v7.4.2","v7.4.3","v7.4.4","v7.5.0","v7.5.1","v7.5.2","v7.5.3"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23950.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L"}]}