Summary
CVE-2026-77814 is a path traversal vulnerability (CWE-22) in infinite-image-browsing, an image/video management application that also ships as a Stable Diffusion WebUI extension. The flaw lies in the is_path_trusted access-control function and allows an unauthenticated remote attacker to read files outside the directories the application is supposed to restrict access to. The issue carries a CVSS v4.0 base score of 8.7 (HIGH).
Technical details
- Root cause:
is_path_trustedinscripts/iib/api.pyvalidates requested paths usingpath.startswith(parent_path)without appending a path separator, so a sibling directory whose name merely begins with an allowed path (e.g./data/images_private) is incorrectly treated as trusted when/data/imagesis the allowed path. - The check also relies on
os.path.normpath, which does not resolve symlinks, so a symlink placed inside an otherwise-allowed directory can be used to point outside it. - Attack vector: network, no authentication or user interaction required; the attacker sends a crafted request to the application’s file-serving endpoint (used by
FileResponse). - Trigger conditions: the vulnerable code path is reachable when access control is enabled (
IIB_ACCESS_CONTROLset to "enable") or when the application is exposed over the network (e.g. viashare,ngrok,listen, orserver_namedeployment options). Note that in default standalone configuration, access control is disabled entirely, which independently exposes all files without authentication. - Impact: disclosure of restricted files on the host filesystem (confidentiality impact only; no impact on integrity or availability per the published vector).
Affected software
- infinite-image-browsing (zanllp/infinite-image-browsing), including its Stable Diffusion WebUI extension form: versions 0 through 1.8.0 (inclusive).
- Vulnerable files:
scripts/iib/api.py,scripts/iib/tool.py.
Severity
- CVSS v4.0: 8.7 (HIGH) —
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - CVSS v3.1: 7.5 (HIGH) —
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Mitigation and recommended actions
- Immediate: upgrade to a version containing the fix committed in
4057a624c7a23a36f0b4dc6a545b40767d602450(merged via pull request #969), which resolves the path-validation flaw for versions beyond 1.8.0. - If patching is not immediately possible: avoid exposing the application to untrusted networks (do not use
share,ngrok,listen, orserver_nameoptions without additional protections); ensure access control is explicitly enabled rather than relying on defaults; place the application behind an authenticating reverse proxy and restrict network access to trusted hosts only.

