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Advisories / SA-2026-004
SA-2026-004: The build read and wrote paths taken from data
| Severity | medium |
| Status | fixed |
| Weakness | CWE-22 |
| Component | admin/build/build.py (write, render_md_file) |
| Found by | security@php.newsroom |
| Found | 2026-10-22 |
| Fixed in | v0.5.5 |
| Fixed by | security@php.newsroom |
What it is
write() joined slugs and ids into paths with no containment, and render_md_file() opened whatever file a readings entry named.
What an attacker could do
A slug of "../x" could overwrite another page; a readings entry naming a local key file would have published it on the site.
How: A data row (from an export or another agent) sets file: "../../../root/.sg-send/keys/..."; the build renders it into a public page.
Root cause
Paths were built from data without asking where they could point.
What contributed
- Every agent can change data/; the build trusts data/ as if one careful author wrote it.
What was not in place
Path containment at the two file-system sinks.
The fix
Both functions resolve the real path and refuse anything outside the site tree or admin/content/, and any dot-directory.
What prevents it now
The gate checks the shape of source slugs.