TOML::XS versions before 0.06 for Perl bundle an unsupported and vulnerable version of tomlc99.
The tomlc99 library is no longer maintained, and has an uncontrolled recursion vulnerability publicly reported in the issue tracker.
Any caller that passes untrusted TOML to from_toml risks a stack overflow from a deeply-nested document.
TOML::XS version 0.06 or later uses the successor tomlc17 library.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
References 6
https://github.com/cktan/tomlc17
9b29abf9-4ab0-4765-b253-1875cd9b441e
https://github.com/cktan/tomlc99/issues/97
9b29abf9-4ab0-4765-b253-1875cd9b441e
https://metacpan.org/release/FELIPE/TOML-XS-0.06/changes
9b29abf9-4ab0-4765-b253-1875cd9b441e
https://raw.githubusercontent.com/cktan/tomlc99/29076dfd095bbbbd50a3c1b2760d29f…
9b29abf9-4ab0-4765-b253-1875cd9b441e
https://toml.io/en/v1.0.0
9b29abf9-4ab0-4765-b253-1875cd9b441e
http://www.openwall.com/lists/oss-security/2026/07/24/4
af854a3a-2127-422b-91ae-364da2661108