{"id":"CVE-2026-23950","title":"node-tar,a Tar for Node.js, has a race condition vulnerability in versions up to and including 7.5.3","summary":"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 normalizatio…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L","cwe":["CWE-176","CWE-352","CWE-367"],"vendor":"isaacs","product":"tar","affected":["tar < 7.5.4"],"patched":["tar 7.5.4"],"published":"2026-01-20","updated":"2026-06-30","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-23950","references":[{"url":"https://github.com/isaacs/node-tar/commit/3b1abfae650056edfabcbe0a0df5954d390521e6","label":"security-advisories@github.com"},{"url":"https://github.com/isaacs/node-tar/security/advisories/GHSA-r6q2-hw4h-h46w","label":"security-advisories@github.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:18480","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:18868","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:2144","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:2926","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:6192","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/security/cve/CVE-2026-23950","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2431036","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-23950.json","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-23950"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23950"}],"tags":["nvd","csaf","vex","red-hat"],"epss":0.00264,"epssPercentile":0.1821,"ingestedAt":"2026-06-30T13:26:50.519Z","slug":"CVE-2026-23950","body":"## Overview\n\nnode-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.\n\n## Affected\n\n- `tar < 7.5.4`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `tar 7.5.4`\n\n## Vendor advisories\n\n- **RHSA-2026:18480** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-05-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:18480)\n- **RHSA-2026:18868** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-05-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:18868)\n- **RHSA-2026:6192** · Red Hat · fixed in: Red Hat OpenShift Dev Spaces 3.27 · released 2026-03-30 · [advisory](https://access.redhat.com/errata/RHSA-2026:6192)\n- **RHSA-2026:2926** · Red Hat · fixed in: Red Hat Trusted Artifact Signer 1.2 · released 2026-02-18 · [advisory](https://access.redhat.com/errata/RHSA-2026:2926)\n- **RHSA-2026:2144** · Red Hat · fixed in: Red Hat Trusted Artifact Signer 1.3 · released 2026-02-05 · [advisory](https://access.redhat.com/errata/RHSA-2026:2144)\n- **Red Hat VEX** · Important · affected: Confidential Compute Attestation, Logging Subsystem for Red Hat OpenShift, Migration Toolkit for Containers, Network Observability Operator, OpenShift Lightspeed, OpenShift Pipelines, … · no fix planned: Red Hat Enterprise Linux 6, Logging Subsystem for Red Hat OpenShift, OpenShift Lightspeed, OpenShift Pipelines, … · updated 2026-10-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-23950.json)","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}