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CVE-2026-109449VulnerabilityPublished Updated

In Symfony Expression Language versions prior to 5.4.54, 6.4.48, 7.4.21, and 8.1.9, the parser of the

Affects symfonySource GCVE Database

0
Authoritative record:CVE-2026-109449· High 8.7

Not known to be exploited · CVSS 8.7 High.

Data as of 29 Oct 2026, 00:13 UTC

CVSS 4.0 base score
8.7High
How severe the flaw is on the 0–10 CVSS scale.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 15 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
Ubuntu 26.10symfonypkg:deb/ubuntu/symfony?arch=source&distro=stonkingOther threatsAffected
  • 7.4.7+dfsg-1ubuntu1 – 7.4.16+dfsg-1ubuntu2
6 affected builds
Fixed in–
Ubuntu 26.04 LTSsymfonypkg:deb/ubuntu/symfony?arch=source&distro=resoluteOther threatsAffected
  • 6.4.24+dfsg-1 – 7.4.7+dfsg-1ubuntu1
4 affected builds
Fixed in–
Ubuntu Pro 24.04 LTSsymfonypkg:deb/ubuntu/symfony?arch=source&distro=esm-apps/nobleOther threatsAffected
  • 5.4.23+dfsg-1ubuntu1 – 6.4.5+dfsg-3ubuntu3+esm1
5 affected builds
Fixed in–
Ubuntu Pro 22.04 LTSsymfonypkg:deb/ubuntu/symfony?arch=source&distro=esm-apps/jammyOther threatsAffected
  • =5.2.6+dfsg-1ubuntu7
  • =5.4.4+dfsg-1ubuntu8
  • =5.4.4+dfsg-1ubuntu8+esm1
Fixed in–
Ubuntu Pro 20.04 LTSsymfonypkg:deb/ubuntu/symfony?arch=source&distro=esm-apps/focalOther threatsAffected
  • 4.3.4+dfsg-1ubuntu1 – 4.3.8+dfsg-1ubuntu1+esm2
4 affected builds
Fixed in–
Ubuntu Pro 18.04 LTSsymfonypkg:deb/ubuntu/symfony?arch=source&distro=esm-apps/bionicOther threatsAffected
  • 2.8.7+dfsg-1.3ubuntu1 – 3.4.6+dfsg-1ubuntu0.1+esm2
6 affected builds
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade Symfony Expression Language to versions 5.4.54, 6.4.48, 7.4.21, or 8.1.9 or later, where the parser includes bounds on node tree depth to prevent crashes. No other mitigation is indicated. Patch status is confirmed by the presence of fixed versions.

Description

Symfony Expression Language versions prior to 5.4.54, 6.4.48, 7.4.21, and 8.1.9 contain a vulnerability where the parser builds an unbounded depth node tree. This can cause the PHP process to crash when parsing expressions with extremely deep nesting of unary operators, array literals, binary operators, or property accesses. Applications that validate or parse untrusted expressions, such as those using #[Assert\ExpressionSyntax], are susceptible to denial-of-service via a single crafted request.

References

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