CVE-2026-77815 is a high-severity (CVSS 7.5) CWE-59 vulnerability. O3 Security confirms whether CVE-2026-77815 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
to_abs_path in scripts/iib/tool.py normalised the requested path with os.path.normpath, which collapses dot segments but does not resolve symbolic links. A symlink placed inside a scanned…
Description
to_abs_path in scripts/iib/tool.py normalised the requested path with os.path.normpath, which collapses dot segments but does not resolve symbolic links. A symlink placed inside a scanned directory therefore satisfies the containment comparison performed by is_path_trusted in scripts/iib/api.py while pointing outside that directory, and FileResponse follows the link when serving the response, so a link created in an image directory and targeting a file such as /etc/passwd discloses that file. Whether the check applies depends on get_enable_access_control in scripts/iib/tool.py: it returns true when IIB_ACCESS_CONTROL is set to enable, false when set to disable, and otherwise true when the host Stable Diffusion WebUI was started with share, ngrok, listen or server_name, falling back to false. Confinement is therefore active in the network-exposed WebUI deployments that rely on it, while a standalone run with no such option serves every readable file regardless of this flaw. The fix resolves the path with os.path.realpath.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-77815 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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 pinpoints whether CVE-2026-77815 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-77815. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-77815 in your dependencies?
O3 detects CVE-2026-77815 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.