CedarPolicy CedarJava up to 2.3.5/3.4.0/4.8.x Cedar Value Types toCedarExpr injection

Summaryinfo

A vulnerability described as critical has been identified in CedarPolicy CedarJava up to 2.3.5/3.4.0/4.8.x. Impacted is the function toCedarExpr of the component Cedar Value Types. Such manipulation leads to injection. This vulnerability is uniquely identified as CVE-2026-55773. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability was found in CedarPolicy CedarJava up to 2.3.5/3.4.0/4.8.x. It has been rated as critical. Affected by this issue is the function toCedarExpr of the component Cedar Value Types. The manipulation with an unknown input leads to a injection vulnerability. Using CWE to declare the problem leads to CWE-74. The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. Impacted is confidentiality, integrity, and availability. CVE summarizes:

CedarJava is an open source Java implementation of the Cedar policy language, used for fine-grained authorization decisions. In versions prior to 2.3.6, 3.4.1 and 4.9.0, under certain circumstances, improper input handling could allow Cedar-expression injection via unescaped toCedarExpr(). The toCedarExpr() method on Cedar Value types does not escape special characters (" or \) when converting values to Cedar source code. If an integrator uses toCedarExpr() to build policy text at runtime from user-controlled values, an actor could inject arbitrary Cedar expressions. For example, injecting || true into a permit ... when { ... } clause could make the permit unconditional, or injecting && false into a forbid clause could prevent the forbid from triggering. This issue requires the integrator to use toCedarExpr() to build policy text at runtime from user-controlled input. This vulnerability has been fixed in versions 2.3.6, 3.4.1, and 4.9.0.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-55773 since 06/17/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1055.

Upgrading to version 2.3.6, 3.4.1 or 4.9.0 eliminates this vulnerability.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Programming Language Software

Vendor

• CedarPolicy

Name

• CedarJava

Version

• 2.3.0
• 2.3.1
• 2.3.2
• 2.3.3
• 2.3.4
• 2.3.5
• 3.0
• 3.1
• 3.2
• 3.3
• 3.4.0
• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion