Arbitrary file write via traversing output names
Published Feb 25, 2026 · Updated Feb 25, 2026
Path traversal in Rollup before 2.80.0, 3.30.0, or 4.59.0 allows attackers to write arbitrary files through crafted output names. Its filename sanitizer leaves periods and separators intact, then writeOutputFile resolves the resulting name against the output directory and writes it without confirming containment. Control of a CLI named input, manual chunk alias, or plugin-provided filename is required; writes are limited to paths permitted to the build process but can replace startup or authorization files and enable persistent code execution.
Summary
What happened
Path traversal in Rollup before 2.80.0, 3.30.0, or 4.59.0 allows attackers to write arbitrary files through crafted output names. Its filename sanitizer leaves periods and separators intact, then writeOutputFile resolves the resulting name against the output directory and writes it without confirming containment. Control of a CLI named input, manual chunk alias, or plugin-provided filename is required; writes are limited to paths permitted to the build process but can replace startup or authorization files and enable persistent code execution.
The record
- CVE
- CVE-2026-27606
- Published
- Feb 25, 2026
- Updated
- Feb 25, 2026
- Vendor
- Rollup
- Product
- Rollup
- Classifications
- CWE-22, T1546.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 25, 2026CVE publishedPublication date reported by the CVE source.
- Feb 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.80.0
- Affected versionversion=>= 3.0.0, < 3.30.0
- Affected versionversion=>= 4.0.0, < 4.59.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Rollup CLI named-input traversal proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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