# CVE-2026-13397: HTML::Bare versions through 0.04 for Perl will hang in an infinite loop when parsing malformed attributes

> An attacker can cause a denial of service by providing malformed HTML attributes that trigger an infinite loop in the HTML::Bare Perl parser.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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:** 16 Jul 2026
- **Updated:** 17 Jul 2026
- **Also known as:** GHSA-xfxg-9rjg-hqrw

## What is CVE-2026-13397?

CVE-2026-13397 is a high-severity denial of service vulnerability in CODECHILD HTML::Bare, published on 16 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

HTML::Bare versions through 0.04 for Perl will hang in an infinite loop when parsing malformed attributes.

The parserc_parse function never advances the attribute-parse state cursor on certain malformed attribute forms, looping forever.

Nameless attributes such as "<a ='c'>" or unbalanced quotes "<a b='''''''c'>" can trigger this condition.

Note that the latest version available on CPAN is version 0.02. Newer versions are available on the git repository.

Weakness: CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2026-13397?


## How do I fix CVE-2026-13397?

No fix has been published for CVE-2026-13397 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-13397 being exploited?

There is no known exploitation of CVE-2026-13397 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-13397 and fix it if it is affected.

What it is: CVE-2026-13397 is a high-severity denial of service vulnerability in CODECHILD HTML::Bare, published on 16 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-2026-13397 in the wild and no public exploit code.

Affected product: CODECHILD HTML::Bare. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-13397/ (Markdown: https://insights.sbomify.com/CVE-2026-13397/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-13397
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-13397
- OSV: https://osv.dev/vulnerability/CVE-2026-13397

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-13397/
Summaries are generated and may contain mistakes; the official description above is the record.