CVE-2026-39369 is a high-severity (CVSS 7.6) Path Traversal vulnerability in WWBN/AVideo. No vendor fix is recorded yet; mitigation options are listed below.
WWBN AVideo's GIF poster fetch bypasses traversal scrubbing and exposes local files through public media URLs
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-39369.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-39369 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 379,145 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
WWBN/AVideoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Summary
objects/aVideoEncoderReceiveImage.json.php allowed an authenticated uploader to fetch attacker-controlled same-origin /videos/... URLs, bypass traversal scrubbing, and expose server-local files through the GIF poster storage path.
The vulnerable GIF branch could be abused to read local files such as /etc/passwd or application source files and republish those bytes through a normal public GIF media URL.
Details
The vulnerable chain was:
objects/aVideoEncoderReceiveImage.json.phpaccepted attacker-controlleddownloadURL_gifimage- traversal scrubbing used
str_replace('../', '', ...), which was bypassable with overlapping input such as....// - same-origin
/videos/...URLs were accepted url_get_contents()andtry_get_contents_from_local()resolved the request into a local filesystem read- the fetched bytes were written into the GIF destination
- invalid GIF cleanup used the wrong variable, so the non-image payload remained on disk
This made the GIF poster path a local file disclosure primitive with public retrieval.
Proof of concept
- Log in as an uploader and create an owned video row through the normal encoder flow.
- Send:
POST /objects/aVideoEncoderReceiveImage.json.php
downloadURL_gifimage=https://localhost/videos/....//....//....//....//....//....//etc/passwd
- Query:
GET /objects/videos.json.php?showAll=1
- Recover the generated GIF URL from
videosURL.gif.url. - Download that GIF URL.
- Observe that the body matches the target local file, such as
/etc/passwd, byte-for-byte.
Impact
An authenticated uploader can read server-local files and republish them through a public GIF media URL by supplying a crafted same-origin /videos/... path to downloadURL_gifimage. Because traversal scrubbing was bypassable and the fetched bytes were written to the GIF destination without effective invalid-image cleanup, successful exploitation allows disclosure of files such as /etc/passwd, readable application source code, or deployment-specific configuration accessible to the application.
Recommended fix
- Reject any remote image URL whose decoded path contains traversal markers
- Do not allow attacker-controlled same-origin
/videos/...fetches to resolve into local file reads - Constrain any local shortcut path handling with
realpath()and strict base-directory allowlists - Validate GIF content before saving it into public media storage
- Ensure invalid-image cleanup checks the correct destination path
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | WWBN/AVideo | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for WWBN/AVideo, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of WWBN/AVideo has shipped for CVE-2026-39369 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
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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-39369 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-39369. 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-2026-39369 in your dependencies?
O3 Security finds CVE-2026-39369 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.