Twig: The `spaceless` filter implicitly marks its output as safe — GHSA-4J38-F5CW-54H7

Summary

### Description The `spaceless` filter is registered with `is_safe => ['html']`, which means Twig's autoescaper does not escape its output in an HTML context. As a result, applying `spaceless` to attacker-controlled input that contains markup emits the markup unescaped even when the developer never wrote `|raw` and autoescape is enabled. Example: ```twig {% set payload = '<script>alert()</script>' %} {{ payload }}…

Timeline

Published by source

2026-05-21

Risk context

• Reported severity or threat level: low.
• Reported CVSS score: 1.3 out of 10.
• Reported EPSS value: 0.
• Review exposure for the affected product or family: composer: twig/twig.

Product

composer: twig/twig

What to do

General, cautious steps (verify details in the official source):

• Review exposure and plan remediation based on risk and environment.
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

Evidence and provenance

Canonical advisory ID

GHSA-4J38-F5CW-54H7

Source

GitHub

Vendor

GitHub

Published by source

2026-05-21

Last source activity

2026-05-21

Additional identifiers

CVE-2026-46628

Curated by

hlukh.ch

Related advisories and connections

These advisories are connected by shared CVE, product, vendor, source, or time signals.