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 378,156 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
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 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.