How severe is CVE-2018-13818?

CVE-2018-13818 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-13818 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-13818?

CVE-2018-13818 affects Symfony Twig. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-13818?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2018-13818 published?

CVE-2018-13818 was published on 2018-07-10 and last updated on 2026-06-17.

CVE-2018-13818

CVE-2018-13818 is a critical-severity vulnerability in Symfony Twig with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-94.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 7% (93rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-94
Affected product: Symfony Twig
Published: 2018-07-10
Last modified: 2026-06-17

Description

Twig before 2.4.4 allows Server-Side Template Injection (SSTI) via the search search_key parameter. NOTE: the vendor points out that Twig itself is not a web application and states that it is the responsibility of web applications using Twig to properly wrap input to it

Frequently asked questions

What is CVE-2018-13818?: Twig before 2.4.4 allows Server-Side Template Injection (SSTI) via the search search_key parameter. NOTE: the vendor points out that Twig itself is not a web application and states that it is the responsibility of web applications using Twig to properly wrap input to it
How severe is CVE-2018-13818?: CVE-2018-13818 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-13818 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-13818?: CVE-2018-13818 affects Symfony Twig. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-13818?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2018-13818 published?: CVE-2018-13818 was published on 2018-07-10 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:symfony:twig:*:*:*:*:*:*:*:*

More vulnerabilities in Symfony Twig

CVE-2026-24425 — High (CVSS 8.8): Twig versions 2.16.x and 3.9.0 through 3.25.x contain a sandbox bypass vulnerability when using a SourcePolicyInterface…
CVE-2022-23614 — High (CVSS 8.8): Twig is an open source template language for PHP. When in a sandbox mode, the `arrow` parameter of the `sort` filter…
CVE-2024-45411 — High (CVSS 8.5): Twig is a template language for PHP. Under some circumstances, the sandbox security checks are not run which allows…
CVE-2022-39261 — High (CVSS 7.5): Twig is a template language for PHP. Versions 1.x prior to 1.44.7, 2.x prior to 2.15.3, and 3.x prior to 3.4.3…
CVE-2001-1537 — High (CVSS 7.5): The default "basic" security setting' in config.php for TWIG webmail 2.7.4 and earlier stores cleartext usernames and…
CVE-2015-7809 — Medium (CVSS 6.8): The displayBlock function Template.php in Sensio Labs Twig before 1.20.0, when Sandbox mode is enabled, allows remote…

All CVEs affecting Symfony Twig →

Other CWE-94 (Code Injection) vulnerabilities

CVE-2026-57624 — Critical (CVSS 10.0): Unauthenticated Remote Code Execution (RCE) in Blocksy Companion Pro <= 2.1.46 versions.
CVE-2026-10134 — Critical (CVSS 10.0): IBM Langflow OSS 1.0.0 through 1.9.3 allows an attacker to read every secret available to the Langflow process, read…
CVE-2026-53576 — Critical (CVSS 10.0): Kestra is an open-source, event-driven orchestration platform. Prior to 1.0.45 and 1.3.21, the authentication filter…
CVE-2026-10561 — Critical (CVSS 10.0): IBM Langflow OSS 1.0.0 through 1.9.3 has an vulnerability due to an improper isolation of Python execution combined…
CVE-2026-25470 — Critical (CVSS 10.0): Improper Control of Generation of Code ('Code Injection') vulnerability in ACPT ACPT (Pro) - Custom Post Types Plugin…
CVE-2026-48836 — Critical (CVSS 10.0): Unauthenticated Remote Code Execution (RCE) in Easy Invoice <= 2.1.19 versions.

Browse all CWE-94 (Code Injection) vulnerabilities →