Is CVE-2026-45133 in the CISA KEV catalog?

No. CVE-2026-45133 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-45133?

CVE-2026-45133 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2026-45133?

CVE-2026-45133 has an EPSS score of 0.69% (49th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-45133?

Upgrade symfony on debian 12 to 5.4.53+dfsg-0+deb12u1 or later.

CVE & CISA-KEV Catalog

CVE-2026-45133

HIGH

7.5

CVSS v3

NVD

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, when the parser is exposed to attacker-controlled input, deeply nested mappings or sequences cause both the block-level (Parser::parseBlock()) and inline (Inline::parseSequence() / Inline::parseMapping()) parsers to recurse without a depth limit. A crafted document exhausts the PHP stack and crashes the worker. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

CWE-674 CWE-776 CWE-1333

How to fix

Remediation Available

symfonyDebian

Fixed in:5.4.53+dfsg-0+deb12u1CVE-2026-45133

Fixed in:6.4.41+dfsg-0+deb13u1CVE-2026-45133

Fixed in:7.4.12+dfsg-1CVE-2026-45133

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

0.69%probability of exploitation in 30 days

49thpercentile

Moderate risk: more likely to be exploited than 49% of all known CVEs.

References

Patch1

github.com

Release Notes4

Related Vulnerabilities

Other CWE-674 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2021-45105	Medium	5.9	100%	-	Fix
CVE-2024-25111	High	8.6	65%	-	Fix
CVE-2023-50269	High	8.6	58%	-	Fix
CVE-2021-42697	High	7.5	36%	-	Fix
CVE-2018-0739	Medium	6.5	19%	-	Fix
CVE-2007-1285	High	7.5	18%	-	Fix

Embed a live status badge for CVE-2026-45133

Markdown

[![CVE-2026-45133](https://tridentstack.com/cve/badge/CVE-2026-45133.svg)](https://tridentstack.com/cve/CVE-2026-45133)

HTML

<a href="https://tridentstack.com/cve/CVE-2026-45133"><img src="https://tridentstack.com/cve/badge/CVE-2026-45133.svg" alt="CVE-2026-45133"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

See how it works Start freeThis CVE lookup is free and always will be.

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-07-15.