CVE-2023-28631

What it is

comrak is a CommonMark + GFM compatible Markdown parser and renderer written in rust. A Comrak AST can be constructed manually by a program instead of parsing a Markdown document with `parse_document`. This AST can then be converted to HTML via `html::format_document_with_plugins`. However, the HTML formatting code assumes that the AST is well-formed. For example, many AST notes contain `[u8]` fields which the formatting code assumes is valid UTF-8 data. Several bugs can be triggered if this is not the case. Version 0.17.0 contains adjustments to the AST, storing strings instead of unvalidated byte arrays. Users are advised to upgrade. Users unable to upgrade may manually validate UTF-8 correctness of all data when assigning to `&[u8]` and `Vec<u8>` fields in the AST. This issue is also tracked as `GHSL-2023-049`.

At a glance

Exploitability

Can be exploited over the network without logging in. Limited direct impact.

Exploit odds

1.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2023-03-28 21:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 05:48 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.3% in the next 30 days (EPSS).
• Severity: 5.3 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2023-03-28 21:15 UTC

Last modified

2026-06-17 05:48 UTC

Exploit probability

1.3% · EPSS, next 30 days

Weakness

CWE-755

Record status

Modified

Affected

• Comrak Project Comrak < 0.17.0

Attack profile CVSS 3.1 · 5.3

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2023-28631.md and follow it. Check whether this project is affected by CVE-2023-28631. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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