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GHSA-w4vp-3mq7-7v82

GHSA-w4vp-3mq7-7v82 is a security vulnerability in lazysizes. O3 Security confirms whether GHSA-w4vp-3mq7-7v82 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Cross-Site Scripting in lazysizes

Published
Sep 3, 2020
Updated
Aug 31, 2020
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Aug 31, 2020 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

227other npm packages depend on this — each one inherits the vulnerability until it's patched upstream
lazysizesnpm
208Kdownloads / week

Description

Versions of lazysizes prior to 5.2.1-rc1 are vulnerable to Cross-Site Scripting. The video-embed plugin fails to sanitize the following attributes: data-vimeo, data-vimeoparams, data-youtube and data-ytparams. This allows attackers to execute arbitrary JavaScript in a victim's browser if the attacker has control over the vulnerable attributes.

Recommendation

Upgrade to version 5.2.1-rc1 or later.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
📦npmlazysizesall versions5.2.1-rc1

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for lazysizes. 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.

  2. Fix

    Update lazysizes to 5.2.1-rc1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-w4vp-3mq7-7v82 is resolved across your whole dependency graph.

  3. Workarounds

    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.

  4. How O3 protects you

    O3 pinpoints whether GHSA-w4vp-3mq7-7v82 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 GHSA-w4vp-3mq7-7v82. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Versions of `lazysizes` prior to 5.2.1-rc1 are vulnerable to Cross-Site Scripting. The `video-embed` plugin fails to sanitize the following attributes: data-vimeo, `data-vimeoparams`, `data-youtube` and `data-ytparams`. This allows attackers to execute arbitrary JavaScript in a victim's browser if the attacker has control over the vulnerable attributes. ## Recommendation Upgrade to version 5.2.1-rc1 or later.
O3 Security · Impact-Aware SCA

Is GHSA-w4vp-3mq7-7v82 in your dependencies?

O3 detects GHSA-w4vp-3mq7-7v82 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

GHSA-w4vp-3mq7-7v82: Cross-Site Scripting… | O3 Security