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TI-2026-83394 Aliases CVE-2026-117645GHSA-jwcv-27cf-c7j5

Attribute injection in Phoenix.HTML via unvalidated attribute names

Priority LOW 24CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Cross-site scripting
Confidentiality · integrity · availability
Low · Low · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79.

Summary

The phoenix_html package affects Phoenix.HTML from 1.0.0 before 3.3.5 and from 4.0.0 before 4.4.0. The attributes_escape/1 function escapes attribute values but not attribute names, so keys built from untrusted input are not neutralized (CWE-79). An attacker who controls attribute names can inject attributes and script into rendered HTML, and user interaction is required.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in phoenixframework phoenix_html allows an attacker who controls attribute names to inject attributes and script into rendered HTML via Phoenix.HTML.attributes_escape/1. attributes_escape/1 in lib/phoenix_html.ex escapes attribute values but not attribute names. key_escape/1 passes a binary key through html_escape, which neutralizes quotes and angle brackets but not whitespace, so a key such as x onmouseover ends the attribute and starts a new one. An atom key is only dasherized, so any character passes, including quotes and >. Nested data, aria and phx keys take the same paths. An application is affected when it builds attribute keys from untrusted input and renders them through HEEx <tag {@attrs}>, content_tag/3, or a direct call. Before 3.0.0 the same code lived in Phoenix.HTML.Tag. This issue affects phoenix_html: from 1.0.0 before 3.3.5 and from 4.0.0 before 4.4.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00315 24th percentileScored 2026-11-07
Fix Fixed phoenix_html (phoenixframework): 3.3.5, 4.4.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
phoenixframeworkphoenix_html1.0.0 to before 3.3.5; 4.0.0 to before 4.4.03.3.5, 4.4.0Patch availableCNA
  • phoenix_html Vendorphoenixframework Affected 1.0.0 to before 3.3.5; 4.0.0 to before 4.4.0 Fixed in 3.3.5, 4.4.0 Patch available CNA

CPE names CNA · 1

CPEVersionsRoleVendor
cpe:2.3:a:phoenixframework:phoenix_html:*:*:*:*:*:*:*:*——phoenixframework
  • cpe:2.3:a:phoenixframework:phoenix_html:*:*:*:*:*:*:*:* Versions — — ·phoenixframework

Remediation

Upgrade phoenix_html to 3.3.5 or 4.4.0, depending on the release line in use. The fixed versions are 3.3.5 and 4.4.0 for phoenix_html.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

  • Fix · CNA phoenix_html (phoenixframework) Fixed in 3.3.5, 4.4.0

Timeline

  1. 2026-10-30 Threatist record created from CVE-2026-117645
  2. 2026-10-30 Alias added: GHSA-jwcv-27cf-c7j5
  3. 2026-11-06 CISA SSVC decision points changed

References

Patch 2

Advisory 1

Other 2

  • TI-2026-40965 Improper check for unusual conditions in phoenixframework phoenix CVSS 4.0MEDIUM 6.3
  • TI-2026-41931 Scheme validation bypass in Phoenix.LiveView.Utils leads to XSS via <.link> CVSS 4.0MEDIUM 5.1
  • TI-2026-40964 Phoenix transports do not limit channel joins per connection, enabling process-exhaustion denial of service CVSS 4.0HIGH 8.7
  • TI-2026-46420 Open redirect in Phoenix.LiveView.validate_local_url!/2 via ASCII tab, LF and CR CVSS 4.0LOW 2.1
  • TI-2026-25181 Long-poll NDJSON body splitting causes unbounded memory allocation in Phoenix CVSS 4.0HIGH 8.7
  • TI-2022-20955 socket/transport.ex in Phoenix before 1.6.14 mishandles check_origin wildcarding. CVSS 3.1HIGH 7.5
See all 8 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences