# CVE-2020-26298: Injection in Redcarpet

> An injection vulnerability in the Redcarpet Ruby library allows attackers to perform cross-site scripting attacks by bypassing HTML escaping mechanisms.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 11 Jan 2021
- **Updated:** 13 Feb 2025
- **Also known as:** DEBIAN-CVE-2020-26298, DLA-2526-1, DSA-4831-1, GHSA-q3wr-qw3g-3p4h, OESA-2021-1175

## What is CVE-2020-26298?

CVE-2020-26298 is a medium-severity cross-site scripting vulnerability in Debian Debian Linux, published on 11 Jan 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Redcarpet is a Ruby library for Markdown processing. In Redcarpet before version 3.5.1, there is an injection vulnerability which can enable a cross-site scripting attack. In affected versions no HTML escaping was being performed when processing quotes. This applies even when the `:escape_html` option was being used. This is fixed in version 3.5.1 by the referenced commit.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2020-26298?

2 open source packages ship an affected version, including redcarpet. It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `redcarpet` | RubyGems | All versions | 3.5.1 |
| `redcarpet` | RubyGems | All versions | 3.5.1 |

Products: Debian Debian Linux, Redcarpet Project Redcarpet.

## How do I fix CVE-2020-26298?

Upgrade redcarpet to 3.5.1 or later.

## Is CVE-2020-26298 being exploited?

There is no known exploitation of CVE-2020-26298 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-26298 and fix it if it is affected.

What it is: CVE-2020-26298 is a medium-severity cross-site scripting vulnerability in Debian Debian Linux, published on 11 Jan 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-26298 in the wild and no public exploit code.

Affected packages and fixed versions:
- redcarpet (RubyGems): affected all versions; fixed in 3.5.1
- redcarpet (RubyGems): affected all versions; fixed in 3.5.1

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-2020-26298/ (Markdown: https://insights.sbomify.com/CVE-2020-26298/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-26298
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-26298
- OSV: https://osv.dev/vulnerability/CVE-2020-26298

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-26298/
Summaries are generated and may contain mistakes; the official description above is the record.