# CVE-2026-56015: Net::IP::LPM versions before 1.11 for Perl allow a heap out-of-bounds read via an unbounded prefix length

> A heap out-of-bounds read in Net::IP::LPM allows attackers to cause a denial of service via crafted prefix lengths.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 Jul 2026
- **Updated:** 7 Sep 2026
- **Also known as:** GHSA-q2wj-rfvr-wf9p

## What is CVE-2026-56015?

CVE-2026-56015 is a critical memory corruption vulnerability, published on 3 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Net::IP::LPM versions before 1.11 for Perl allow a heap out-of-bounds read via an unbounded prefix length.

add() passes the prefix string to the trie builder addPrefixToTrie() without checking it against the address width.

addPrefixToTrie() then walks the prefix buffer by prefix_length bits, reading prefix[byte] for byte up to prefix_len/8, where prefix is the 4-byte (IPv4) or 16-byte (IPv6) packed address. A prefix length greater than 32 for IPv4 or 128 for IPv6, for example add("1.2.3.4/255", $v) or add("2001:db8::/255", $v), reads past the end of the packed address.

The out-of-bounds read happens during trie construction and is bounded: the prefix length is stored as an unsigned char, so the bit walk reads at most 32 bytes from the start of the packed address, a short distance past the end of the 4-byte or 16-byte buffer. It is detectable under AddressSanitizer, valgrind, or a hardened allocator, where it can abort the process. Lookups and dump() format only the valid address width, so the out-of-bounds bytes are not exposed through the module's API.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-56015?


## How do I fix CVE-2026-56015?

No fix has been published for CVE-2026-56015 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-56015 being exploited?

There is no known exploitation of CVE-2026-56015 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-56015 and fix it if it is affected.

What it is: CVE-2026-56015 is a critical memory corruption vulnerability, published on 3 Jul 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-2026-56015 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-2026-56015/ (Markdown: https://insights.sbomify.com/CVE-2026-56015/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-56015
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-56015
- OSV: https://osv.dev/vulnerability/CVE-2026-56015

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-56015/
Summaries are generated and may contain mistakes; the official description above is the record.