What’s Vulnerable › Vulnerabilities

CVE-2026-14803: Mojo::JSON versions before 9.47 for Perl allow memory exhaustion via unbounded recursion in the pure-Perl decoder

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-06 · updated 2026-10-25
• Weakness: CWE-674

Description

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.

Affected products

• SRI Mojo::JSON: before 9.47 — fixed in 9.47

How to fix

Upgrade to a fixed version: SRI Mojo::JSON 9.47. Check the vendor advisory for mitigations.

References

• https://github.com/mojolicious/mojo/commit/cc38b0554275c4d84f6b8b49bcbbc1bec2068fe1.patch
• https://metacpan.org/release/SRI/Mojolicious-9.47/changes
• http://www.openwall.com/lists/oss-security/2026/07/06/2

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