CVE-2026-80490 Algorithm::AhoCorasick::XS versions through 0.04 for Perl read the haystack string length before the scalar is stringified.
An attacker can cause a denial of service by passing numeric or object inputs to the AhoCorasick matching methods, triggering an out-of-bounds read and process abort.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-80490?
CVE-2026-80490 is a memory corruption vulnerability, published on 30 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Algorithm::AhoCorasick::XS versions through 0.04 for Perl read the haystack string length before the scalar is stringified.
The matches, first_match and match_details methods use the T_STD_STRING typemap to translate Perl scalars (SVs) into strings via the std::string constructor, using the SvPV macro to stringify the haystack input, and the SvCUR macro to determine the length of the SV.
When the input SVs are references, integers (IVs) or floats (NVs), the SvCUR macro will return an invalid length if it is run before the input is stringified, leading to an out-of-bounds read which can abort the process.
Note that the evaluation order of arguments to std::string is unspecified. Depending on the compiler, SvCUR may be run first and lead to an abort that cannot be caught within Perl.
This can be triggered when the haystack is a numeric value, for example,
my $ac = Algorithm::AhoCorasick::XS->new( [ "11", "22" ] ); $ac->matches( 211 );
This can occur when the haystack is the result of reading data from decoded JSON or a numeric database column. It can also be triggered when using a blessed object as a haystack.
Weakness: CWE-125
Which versions are affected by CVE-2026-80490?
How do I fix CVE-2026-80490?
No fix has been published for CVE-2026-80490 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-80490 being exploited?
There is no known exploitation of CVE-2026-80490 in the wild and no public exploit code.
Sources
Also known as GHSA-pfmw-49c5-8vv3.