# 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.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 30 Sep 2026
- **Updated:** 30 Sep 2026
- **Also known as:** GHSA-pfmw-49c5-8vv3

## 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 (Out-of-bounds Read)

## 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.

## Is CVE-2026-80490 being exploited?

There is no known exploitation of CVE-2026-80490 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80490 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-80490 in the wild and no public exploit code.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-80490/ (Markdown: https://insights.sbomify.com/CVE-2026-80490/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80490
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80490
- OSV: https://osv.dev/vulnerability/CVE-2026-80490

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-80490/
Summaries are generated and may contain mistakes; the official description above is the record.