CVE-2026-45133

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...

CVE-2026-45305 Symfony: YAML Parser ReDoS via Catastrophic Backtracking in Parser::cleanup() Regex

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,...

CVE-2026-45133 Symfony: [Yaml] Harden the parser when handling untrusted input

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...

Symfony's YAML Parser Vulnerable to Exponential Memory Allocation via Recursive Collection-Alias Expansion ("Billion Laughs")

Description Symfony\Component\Yaml\Parser resolves YAML aliases anchor during parsing. Aliases that reference collections arrays, stdClass, TaggedValue-wrapped collections can themselves point to other collections containing aliases, creating exponential expansion at resolution time. A small inpu...

PT-2026-44150

Name of the Vulnerable Software and Affected Versions Symfony versions prior to 5.4.31 Description The cleanup function in SymfonyComponentYamlParser contains regular expressions with overlapping quantifiers, specifically in the pattern used to strip the %YAML directive header. This leads to...

Uncontrolled Recursion

Overview Affected versions of this package are vulnerable to Uncontrolled Recursion via Unbounded Recursion in Nested Blocks, Sequences, and Mappings. Symfony\Component\Yaml\Parser is the entry point for parsing YAML strings into PHP values via Yaml::parse. When the parser is exposed to...