How severe is CVE-2026-45305?

CVE-2026-45305 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-45305 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-45305?

CVE-2026-45305 affects Sensiolabs Symfony. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-45305?

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

When was CVE-2026-45305 published?

CVE-2026-45305 was published on 2026-07-14 and last updated on 2026-07-15.

CVE-2026-45305

CVE-2026-45305 is a high-severity vulnerability in Sensiolabs Symfony with a CVSS 3.x base score of 7.5. 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-1333.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.7
EPSS exploit prediction: 1% (54th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-1333
Affected product: Sensiolabs Symfony
Published: 2026-07-14
Last modified: 2026-07-15

Description

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, Symfony\Component\Yaml\Parser::cleanup() used regular expressions with overlapping quantifiers for YAML directive, comment, and document marker cleanup, allowing crafted input to make parsing hang for an arbitrarily long time. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

Frequently asked questions

What is CVE-2026-45305?: Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, Symfony\Component\Yaml\Parser::cleanup() used regular expressions with overlapping quantifiers for YAML directive, comment, and document marker cleanup, allowing crafted input to make parsing hang for an arbitrarily long time. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.
How severe is CVE-2026-45305?: CVE-2026-45305 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-45305 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-45305?: CVE-2026-45305 affects Sensiolabs Symfony. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-45305?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-45305 published?: CVE-2026-45305 was published on 2026-07-14 and last updated on 2026-07-15.

References

Affected products (1)

cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*

More vulnerabilities in Sensiolabs Symfony

CVE-2026-47767 — Critical (CVSS 9.8): Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 5.4.46 until…
CVE-2019-18889 — Critical (CVSS 9.8): An issue was discovered in Symfony 3.4.0 through 3.4.34, 4.2.0 through 4.2.11, and 4.3.0 through 4.3.7. Serializing…
CVE-2019-11325 — Critical (CVSS 9.8): An issue was discovered in Symfony before 4.2.12 and 4.3.x before 4.3.8. The VarExport component incorrectly escapes…
CVE-2017-11365 — Critical (CVSS 9.8): Certain Symfony products are affected by: Incorrect Access Control. This affects Symfony 2.7.30 and Symfony 2.8.23 and…
CVE-2019-10913 — Critical (CVSS 9.8): In Symfony before 2.7.51, 2.8.x before 2.8.50, 3.x before 3.4.26, 4.x before 4.1.12, and 4.2.x before 4.2.7, HTTP…
CVE-2019-10910 — Critical (CVSS 9.8): In Symfony before 2.7.51, 2.8.x before 2.8.50, 3.x before 3.4.26, 4.x before 4.1.12, and 4.2.x before 4.2.7, when…

All CVEs affecting Sensiolabs Symfony →

Other CWE-1333 vulnerabilities

CVE-2026-35458 — Critical (CVSS 9.8): Gotenberg is an API for converting document formats. In 8.29.1 and earlier, Gotenberg uses dlclark/regexp2 to compile…
CVE-2023-29486 — Critical (CVSS 9.8): An issue was discovered in Heimdal Thor agent versions 3.4.2 and before 3.7.0 on Windows, allows attackers to bypass…
CVE-2026-25547 — Critical (CVSS 9.2): @isaacs/brace-expansion is a hybrid CJS/ESM TypeScript fork of brace-expansion. Prior to version 5.0.1,…
CVE-2023-29487 — Critical (CVSS 9.1): An issue was discovered in Heimdal Thor agent versions 3.4.2 and before on Windows and 2.6.9 and before on macOS,…
CVE-2026-71190 — High (CVSS 8.7): In OpenStack Swift through 2.38.0, the proxy server Accept header parser contains a regular expression vulnerable to…
CVE-2026-57584 — High (CVSS 8.7): Phalcon is a high-performance, full-stack PHP framework. Prior to 5.15.0, every Phalcon MVC application built with a…

Browse all CWE-1333 vulnerabilities →