How severe is CVE-2026-26960?

CVE-2026-26960 has a CVSS score of 7.1/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-26960?

CVE-2026-26960 affects the following packages: tar (npm). Ecosystems affected: npm.

How do I fix CVE-2026-26960?

Update tar to 7.5.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-26960 is resolved across your whole dependency graph.

How do I detect CVE-2026-26960 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tar, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-26960 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-26960?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-26960 can be triaged on real exposure rather than presence alone.

Is CVE-2026-26960 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-26960 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-26960?

CVE-2026-26960 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 22th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-26960?

CVE-2026-26960 is classified as Path Traversal (CWE-22). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-26960 published, and has it been updated?

CVE-2026-26960 was published on February 20, 2026 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

HIGH severity

CVE-2026-26960 — tar

HIGHFix: isaacs/node-tar@2cb1120

CVE-2026-26960 is a high-severity (CVSS 7.1) Path Traversal vulnerability in tar. A fix is available for tar — see the affected versions and patch details below.

node-tar has Arbitrary File Read/Write via Hardlink Target Escape Through Symlink Chain in Extraction

Also known asGHSA-83g3-92jg-28cx

Published

Feb 20, 2026

Updated

Aug 12, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-26960.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs22th percentile — riskier than 22% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2026-26960 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

8Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream

tarnpm

65.8Mdownloads / week

Description

Summary

tar.extract() in Node tar allows an attacker-controlled archive to create a hardlink inside the extraction directory that points to a file outside the extraction root, using default options.

This enables arbitrary file read and write as the extracting user (no root, no chmod, no preservePaths).

Severity is high because the primitive bypasses path protections and turns archive extraction into a direct filesystem access primitive.

Details

The bypass chain uses two symlinks plus one hardlink:

a/b/c/up -> ../..
a/b/escape -> c/up/../..
exfil (hardlink) -> a/b/escape/<target-relative-to-parent-of-extract>

Why this works:

Linkpath checks are string-based and do not resolve symlinks on disk for hardlink target safety.
- See STRIPABSOLUTEPATH logic in:
  - ../tar-audit-setuid - CVE/node_modules/tar/dist/commonjs/unpack.js:255
  - ../tar-audit-setuid - CVE/node_modules/tar/dist/commonjs/unpack.js:268
  - ../tar-audit-setuid - CVE/node_modules/tar/dist/commonjs/unpack.js:281
Hardlink extraction resolves target as path.resolve(cwd, entry.linkpath) and then calls fs.link(target, destination).
- ../tar-audit-setuid - CVE/node_modules/tar/dist/commonjs/unpack.js:566
- ../tar-audit-setuid - CVE/node_modules/tar/dist/commonjs/unpack.js:567
- ../tar-audit-setuid - CVE/node_modules/tar/dist/commonjs/unpack.js:703
Parent directory safety checks (mkdir + symlink detection) are applied to the destination path of the extracted entry, not to the resolved hardlink target path.
- ../tar-audit-setuid - CVE/node_modules/tar/dist/commonjs/unpack.js:617
- ../tar-audit-setuid - CVE/node_modules/tar/dist/commonjs/unpack.js:619
- ../tar-audit-setuid - CVE/node_modules/tar/dist/commonjs/mkdir.js:27
- ../tar-audit-setuid - CVE/node_modules/tar/dist/commonjs/mkdir.js:101

As a result, exfil is created inside extraction root but linked to an external file. The PoC confirms shared inode and successful read+write via exfil.

PoC

hardlink.js Environment used for validation:

Node: v25.4.0
tar: 7.5.7
OS: macOS Darwin 25.2.0
Extract options: defaults (tar.extract({ file, cwd }))

Steps:

Prepare/locate a tar module. If require('tar') is not available locally, set TAR_MODULE to an absolute path to a tar package directory.
Run:

TAR_MODULE="$(cd '../tar-audit-setuid - CVE/node_modules/tar' && pwd)" node hardlink.js

Expected vulnerable output (key lines):

same_inode=true
read_ok=true
write_ok=true
result=VULNERABLE

Interpretation:

same_inode=true: extracted exfil and external secret are the same file object.
read_ok=true: reading exfil leaks external content.
write_ok=true: writing exfil modifies external file.

Impact

Vulnerability type:

Arbitrary file read/write via archive extraction path confusion and link resolution.

Who is impacted:

Any application/service that extracts attacker-controlled tar archives with Node tar defaults.
Impact scope is the privileges of the extracting process user.

Potential outcomes:

Read sensitive files reachable by the process user.
Overwrite writable files outside extraction root.
Escalate impact depending on deployment context (keys, configs, scripts, app data).

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`tar`	all versions	7.5.8`npm install tar@7.5.8`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tar, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tar to 7.5.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-26960 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-26960 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2026-26960. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

In Red Hat environments, this condition introduces a significant constraint, as exploitation requires user interaction and reliance on unsafe handling of externally supplied archives. The attack is not remotely exploitable in isolation and depends on a user or service processing attacker-controlled input. Furthermore,…

Product	Fixed in	Advisory
Network Observability (NETOBSERV) 1.11.0	`network-observability/network-observability-console-plugin-rhel9:1774431617`	RHSA-2026:6428
Red Hat OpenShift Dev Spaces 3.27	`devspaces/code-rhel9:1774448966`	RHSA-2026:6192
Red Hat Trusted Artifact Signer 1.3	`rhtas/rekor-search-ui-rhel9:1773308315`	RHSA-2026:5447

Frequently Asked Questions

### Summary `tar.extract()` in Node `tar` allows an attacker-controlled archive to create a hardlink inside the extraction directory that points to a file outside the extraction root, using default options. This enables **arbitrary file read and write** as the extracting user (no root, no chmod, no `preservePaths`). Severity is high because the primitive bypasses path protections and turns archive extraction into a direct filesystem access primitive. ### Details The bypass chain uses two symlinks plus one hardlink: 1. `a/b/c/up -> ../..` 2. `a/b/escape -> c/up/../..` 3. `exfil` (hardlink)

O3 Security · Impact-Aware SCA

Is CVE-2026-26960 in your dependencies?

O3 Security finds CVE-2026-26960 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works

CVSS Score

7.1/10CVSS v3 base

Vector breakdown

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Raw vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

CWE Classification

CWE-22Path Traversal

Weaponization

No known public exploit tooling found.

Timeline

Disclosed

Feb 20, 2026

Last updated

Aug 12, 2026

Identifiers

CVE-2026-26960

GHSA-83g3-92jg-28cx

References

Advisorygithub.com Advisorygithub.com Advisorynvd.nist.gov Fixgithub.com Fixgithub.com Packagegithub.com

Related vulnerabilities

This CVE is high severity; 5 of 8 other CVEs affecting tar are rated as high or higher (top: critical).

CVE-2026-73566CVE-2026-59873CVE-2026-59874CVE-2026-59875CVE-2026-59871CVE-2026-53655CVE-2026-31802CVE-2026-29786

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedAug 12, 2026