Mojo::JSON up to 9.46 Perl Decoder _decode_value memory allocation

Summaryinfo

A vulnerability identified as problematic has been detected in Mojo::JSON up to 9.46. The impacted element is the function _decode_value of the component Perl Decoder. The manipulation leads to memory allocation. This vulnerability is uniquely identified as CVE-2026-14803. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Mojo::JSON up to 9.46. This issue affects the function _decode_value of the component Perl Decoder. The manipulation with an unknown input leads to a memory allocation vulnerability. Using CWE to declare the problem leads to CWE-789. The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. Impacted is availability. The summary by CVE is:

Mojo::JSON versions before 9.47 for Perl allow memory exhaustion via unbounded recursion in the pure-Perl decoder. The pure-Perl decode path (`_decode_value` dispatching to `_decode_array` and `_decode_object`) recurses with no depth limit, so a small deeply nested JSON document can consume excessive memory. This path is the default when Cpanel::JSON::XS is not installed or `MOJO_NO_JSON_XS=1` is set; the Cpanel::JSON::XS fast path is not affected. Any caller that decodes an untrusted JSON body, for example `Mojo::Message::json` reached through `$c->req->json`, can exhaust process memory and cause denial of service.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-14803 since 07/05/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 325357 (Linux Distros Unpatched Vulnerability : CVE-2026-14803), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 9.47 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (325357) and EUVD (EUVD-2026-41798). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

• Mojo::JSON

Version

• 9.0
• 9.1
• 9.2
• 9.3
• 9.4
• 9.5
• 9.6
• 9.7
• 9.8
• 9.9
• 9.10
• 9.11
• 9.12
• 9.13
• 9.14
• 9.15
• 9.16
• 9.17
• 9.18
• 9.19
• 9.20
• 9.21
• 9.22
• 9.23
• 9.24
• 9.25
• 9.26
• 9.27
• 9.28
• 9.29
• 9.30
• 9.31
• 9.32
• 9.33
• 9.34
• 9.35
• 9.36
• 9.37
• 9.38
• 9.39
• 9.40
• 9.41
• 9.42
• 9.43
• 9.44
• 9.45
• 9.46

CPE 2.3info

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CPE 2.2info

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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