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Not in CISA KEV

GHSA-j3gg-r6gp-95q2 phoenix_html

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.

XSS in HEEx class attributes

Published
Apr 12, 2022
Updated
Sep 10, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 21, 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 CVEs35th percentile — riskier than 35% of all scored CVEsHighest risk

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.

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

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

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
💧Hexphoenix_htmlall versions3.0.4mix deps.update phoenix_html

Detection & mitigation playbook

Open-source dependency
  1. 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.

  2. 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.

  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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-j3gg-r6gp-95q2 can be triaged on real exposure rather than presence alone.

Tailored to GHSA-j3gg-r6gp-95q2. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

The `class` attribute was not protected against XSS attacks when using HEEx.
O3 Security · Impact-Aware SCA

Is GHSA-j3gg-r6gp-95q2 in your dependencies?

O3 Security finds GHSA-j3gg-r6gp-95q2 across Hex dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-j3gg-r6gp-95q2: phoenix_html XSS | O3 Security