How severe is CVE-2026-104478?

No CVSS score has been assigned to CVE-2026-104478 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-104478?

Affected package information for CVE-2026-104478 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2026-104478?

Upgrade the affected component to the fixed release for CVE-2026-104478, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.

How do I detect CVE-2026-104478 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2026-104478 if there is no patch (or I can't update yet)?

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Is CVE-2026-104478 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-104478 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-2026-104478?

CVE-2026-104478 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 27th 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-2026-104478?

CVE-2026-104478 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-2026-104478 published, and has it been updated?

CVE-2026-104478 was published on October 2, 2026 and was last updated on October 7, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-104478: formwork Path Traversal

Exploitation Status

No confirmed exploitation observed yet

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-2026-104478.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs27th percentile — riskier than 27% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Description

Formwork before 2.3.13 contains a path traversal vulnerability in BackupController that allows authenticated panel users to read or delete arbitrary files. Attackers with backup download or delete permission can supply a base64-encoded backslash-separated traversal payload that bypasses PHP basename on Linux to access files outside the backup directory.

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Fix
Upgrade the affected component to the fixed release for CVE-2026-104478, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Frequently Asked Questions

Formwork before 2.3.13 contains a path traversal vulnerability in BackupController that allows authenticated panel users to read or delete arbitrary files. Attackers with backup download or delete permission can supply a base64-encoded backslash-separated traversal payload that bypasses PHP basename on Linux to access files outside the backup directory.

O3 Security · Impact-Aware SCA

Is CVE-2026-104478 in your dependencies?

Find it across , including transitive dependencies.

Scan my dependencies How O3 SCA works

CVE-2026-104478 — formwork