RUSTSEC-2026-0009

Denial of Service via Stack Exhaustion

## Impact When user-provided input is provided to any type that parses with the RFC 2822 format, a denial of service attack via stack exhaustion is possible. The attack relies on formally deprecated and rarely-used features that are part of the RFC 2822 format used in a malicious manner. Ordinary, non-malicious input will never encounter this scenario. ## Patches A limit to the depth of recursion was added in v0.3.47. From this version, an error will be returned rather than exhausting the stack. ## Workarounds Limiting the length of user input is the simplest way to avoid stack exhaustion, as the amount of the stack consumed would be at most a factor of the length of the input.