CVE-2026-107373: ExtUtils::Typemaps::STL::String versions before 1.06 for Perl T_STD_STRING typemap may read the SV length before stringifying the argument

Severity: critical (CVSS 9.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-10 · updated 2026-10-16
Weakness: CWE-125

Description

ExtUtils::Typemaps::STL::String versions before 1.06 for Perl T_STD_STRING typemap may read the SV length before stringifying the argument. The typemap uses $var = std::string( SvPV_nolen($arg), SvCUR($arg) ) However, evaluation order for C++ arguments is not specified, and some compilers may produce code that evalutes SvCUR($arg) first. When $arg is not a string (for example, an interger, number or a reference) then SvCUR will return an invalid value, and the program may abort or segfault.

Affected products

ExtUtils-Typemaps-Default: before 1.06 — fixed in 1.06

How to fix

Upgrade to a fixed version: ExtUtils-Typemaps-Default 1.06. Check the vendor advisory for mitigations.

References

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