devalue denial of service via sparse array serialization before 5.6.3

high severity · published 2026-11-08

Serializing a sparse array with devalue's uneval or stringify functions consumes excessive CPU and memory. An attacker who can get such a value serialized on your server can cause a denial of service.

Fixed in: 5.6.3

CVE: CVE-2026-123569

Source: NVD

Am I affected?

You are affected if the installed version is older than 5.6.3. Check the version you have and update to 5.6.3 or later. The fixed version is verified against a vendor or advisory source.

Get the fix

FixLane has a reviewed fix procedure for this incident: a read-only check first, then the fix. Ask the Telegram bot, or connect an AI agent to the FixLane MCP server and call get_fix_prompt with incident id 1839 and your operating system.