How severe is GHSA-j3gg-r6gp-95q2?

No CVSS score has been assigned to GHSA-j3gg-r6gp-95q2 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-j3gg-r6gp-95q2?

GHSA-j3gg-r6gp-95q2 affects the following packages: phoenix_html (Hex). Ecosystems affected: Hex.

How do I fix GHSA-j3gg-r6gp-95q2?

Update phoenix_html to 3.0.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j3gg-r6gp-95q2 is resolved across your whole dependency graph.

How do I detect GHSA-j3gg-r6gp-95q2 in my Hex dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for phoenix_html, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-j3gg-r6gp-95q2 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is GHSA-j3gg-r6gp-95q2 actively exploited in the wild?

No public exploit code has been indexed for GHSA-j3gg-r6gp-95q2 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-j3gg-r6gp-95q2?

GHSA-j3gg-r6gp-95q2 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 38th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-j3gg-r6gp-95q2?

GHSA-j3gg-r6gp-95q2 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was GHSA-j3gg-r6gp-95q2 published, and has it been updated?

GHSA-j3gg-r6gp-95q2 was published on April 12, 2022 and was last updated on September 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💧 Hex

Not in CISA KEV

XSS in HEEx class attributesGHSA-j3gg-r6gp-95q2

Fix: phoenixframework/phoenix_html@62a0139

GHSA-j3gg-r6gp-95q2 is a Cross-site Scripting (XSS) vulnerability in phoenix_html. A fix is available for phoenix_html — see the affected versions and patch details below.

Also known asCVE-2021-46871 GHSA-5g2h-9x5v-5h3x

Published

Apr 12, 2022

Updated

Sep 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 2, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-j3gg-r6gp-95q2.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs38th percentile — riskier than 38% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

💧phoenix_html

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Hex packages — download data is not available via public APIs for these ecosystems.

Description

tag.ex in Phoenix Phoenix.HTML (aka phoenix_html) before 3.0.4 allows XSS in HEEx class attributes.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
💧Hex	`phoenix_html`	all versions	3.0.4`mix deps.update phoenix_html`

Affected Products

1 product · 1 configurations

Application

phoenix htmlphoenixframework

< 3.0.4

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for phoenix_html, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update phoenix_html to 3.0.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j3gg-r6gp-95q2 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

The `class` attribute was not protected against XSS attacks when using HEEx.

O3 Security · Impact-Aware SCA

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