# CVE-2026-72888: Net::OAuth versions before 0.32 for Perl allow memory exhaustion via unbounded caching of failed module loads in smart_require.

> Remote attackers can exhaust server memory by sending crafted OAuth messages, causing denial of service in applications using Net::OAuth.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-72888, GHSA-m2cv-cq5x-47ph, UBUNTU-CVE-2026-72888

## What is CVE-2026-72888?

CVE-2026-72888 is a medium-severity denial of service vulnerability, published on 16 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Net::OAuth versions before 0.32 for Perl allow memory exhaustion via unbounded caching of failed module loads in smart_require.

smart_require stores results in a process-global hash with no bound and no eviction, and keeps an entry for every class name it is asked about, including names that failed to load, because the return value of the failed eval is stored before the error is checked. The key comes off the wire on the server side: _signature_method_class builds the class name from the signature_method parameter of the incoming message, and verify resolves it before any signature is checked.

A remote client chooses both how many entries are created and how long each key is. In a persistent server the hash grows for the life of the worker process until it exhausts memory. Header size limits bound the key length on the Authorization header path, but not on a POST body.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-72888?


## How do I fix CVE-2026-72888?

Upgrade to a fixed version.

## Is CVE-2026-72888 being exploited?

There is no known exploitation of CVE-2026-72888 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72888 and fix it if it is affected.

What it is: CVE-2026-72888 is a medium-severity denial of service vulnerability, published on 16 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-72888 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-2026-72888/ (Markdown: https://insights.sbomify.com/CVE-2026-72888/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72888
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72888
- OSV: https://osv.dev/vulnerability/CVE-2026-72888

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72888/
Summaries are generated and may contain mistakes; the official description above is the record.