Deserialization of Untrusted Data Affecting symfony/monolog-bridge package, versions <5.4.52>=6.0.0-BETA1, <6.4.40>=7.0.0-BETA1, <7.4.12>=8.0.0-BETA1, <8.0.12
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published24 May 2026
- disclosed20 May 2026
- creditToàn Thắng, Sam Sanoop
Introduced: 20 May 2026
CVE-2026-45077 (opens in a new tab)How to fix?
Upgrade symfony/monolog-bridge to version 5.4.52, 6.4.40, 7.4.12, 8.0.12 or higher.
Overview
symfony/monolog-bridge is a Provides integration for Monolog with various Symfony components
Affected versions of this package are vulnerable to Deserialization of Untrusted Data via deserialization of network input in Symfony\Bridge\Monolog\Command\ServerLogCommand. An attacker can trigger PHP object injection by sending crafted serialized payloads to the server:log TCP listener, as received messages are processed using unserialize(base64_decode(...)) without authentication, integrity validation, or allowed_classes restrictions.
This can lead to unauthenticated denial of service and, depending on available gadget chains in the target environment, potentially remote code execution through magic methods such as __wakeup() or __destruct().
Details
Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating object from sequence of bytes is called deserialization. Serialization is commonly used for communication (sharing objects between multiple hosts) and persistence (store the object state in a file or a database). It is an integral part of popular protocols like Remote Method Invocation (RMI), Java Management Extension (JMX), Java Messaging System (JMS), Action Message Format (AMF), Java Server Faces (JSF) ViewState, etc.
Deserialization of untrusted data (CWE-502) is when the application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, thus allowing the attacker to control the state or the flow of the execution.