CVE-2026-46634: Twig is a template language for PHP

This month

CRITICAL 9.8REMOTEUPGRADE

CVE-2026-46634 is a critical-severity flaw (CVSS 9.8) affecting twig. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Twig is a template language for PHP. From 3.9.0 until 3.26.0, template_from_string() compiles an inner template under a synthesized __string_template__<hash> name that can fall outside a SourcePolicyInterface sandbox decision, allowing a sandboxed template that can call template_from_string and include to render an inner template without security policy enforcement. This issue is fixed in version 3.26.0.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 51%)
CISA exploited list	No
Weakness	CWE-693
Published	2026-07-14
Last modified	2026-10-24

Publisher (CNA): GitHub, Inc. · Vendor: symfony

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-14 22:16 UTCPublished CVE record published
2026-10-24 22:10 UTCUpdated Record last modified

symfony twig UPGRADE

Affected: >= 3.9.0 and < 3.26.0

Fixed in: 3.26.0

Safe to downgrade to: a release before 3.9.0

1. Check installed version

apt-cache policy twig || rpm -q twig || twig --version

2. UPGRADE to 3.26.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade twig

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade twig

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.9.0 (Debian / Ubuntu)

apt-cache madison twig sudo apt install twig=<VERSION_BEFORE_3.9.0> sudo apt-mark hold twig

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list twig sudo dnf downgrade twig-<VERSION_BEFORE_3.9.0> sudo dnf versionlock add twig

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Composer (PHP) · twig/twig · FIXED · 3.26.0 · vulnerable: >= 3.9.0, < 3.26.0 · source

composer require "twig/twig:>=3.26.0"

Fedora 46 · conda · FIXED · 26.9.4-2.fc46 · FEDORA-2026-09931756f1 · source

sudo dnf upgrade --advisory=FEDORA-2026-09931756f1

Debian 12 · php-twig · NOT AFFECTED

Debian 13 · php-twig · FIXED · 3.27.0-0+deb13u1

sudo apt update && sudo apt install --only-upgrade php-twig dpkg --compare-versions "$(dpkg-query -W -f='${Version}' php-twig)" ge "3.27.0-0+deb13u1" && echo PATCHED || echo STILL-VULNERABLE

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-46634?

twig: upgrade to 3.26.0. Exact commands for each OS are on this page.

Is CVE-2026-46634 being exploited?

CVE-2026-46634 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-46634 affect?

CVE-2026-46634 affects twig. Severity is critical (CVSS 9.8). Twig is a template language for PHP. From 3.9.0 until 3.26.0, template_from_string() compiles an inner template under a synthesized __string_template__<hash> name that can fall outside a SourcePolicyInterface sandbox decision, allowing a sa

How urgent is CVE-2026-46634?

Priority 52/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

PHP vulnerabilities

Related CVEs

CVE-2026-46633 CRITICAL 9.8 UPGRADE Twig is a template language for PHP
CVE-2026-48805 CRITICAL 9.1 UPGRADE Twig is a template language for PHP
CVE-2026-48806 CRITICAL 9.1 UPGRADE Twig is a template language for PHP
CVE-2026-48807 CRITICAL 9.1 UPGRADE Twig is a template language for PHP
CVE-2026-46640 HIGH 8.8 UPGRADE Twig is a template language for PHP

References

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