# CVE-2025-0825: CRLF injection in Cpp-httplib

> Attackers can inject CRLF characters to cause HTTP response splitting and XSS in applications using the cpp-httplib library.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 4 Feb 2025
- **Updated:** 23 May 2025
- **Also known as:** DEBIAN-CVE-2025-0825, GHSA-65rj-829h-6g8x, OESA-2025-1116, OESA-2025-1117, OESA-2025-1118, OESA-2025-1119

## What is CVE-2025-0825?

CVE-2025-0825 is a medium-severity vulnerability in yhirose:cpp-httplib, published on 4 Feb 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

cpp-httplib version v0.17.3 through v0.18.3 fails to filter CRLF characters ("\r\n") when those are prefixed with a null byte. This enables attackers to exploit CRLF injection that could further lead to HTTP Response Splitting, XSS, and more.

Weakness: CWE-113 (Improper Neutralization of CRLF Sequences in HTTP Headers)

## Which versions are affected by CVE-2025-0825?

It affects 1 product.


Products: Yhirose Cpp-Httplib.

## How do I fix CVE-2025-0825?

Apply the vendor's patch.

## Is CVE-2025-0825 being exploited?

There is no known exploitation of CVE-2025-0825 in the wild and no public exploit code.

## Other vulnerabilities in yhirose:cpp-httplib

- [CVE-2025-66570](https://insights.sbomify.com/CVE-2025-66570/): cpp-httplib Untrusted HTTP Header Handling: Internal Header Shadowing (REMOTE*/LOCAL*) (critical 10.0)
- [CVE-2026-45372](https://insights.sbomify.com/CVE-2026-45372/): cpp-httplib: HTTP header value percent-decoding in server-side `parse_header` enables CRLF injection (critical 9.9)
- [CVE-2026-46527](https://insights.sbomify.com/CVE-2026-46527/): Null dereference in cpp-httplib (high 8.7)
- [CVE-2026-32627](https://insights.sbomify.com/CVE-2026-32627/): cpp-httplib has a Silent TLS Certificate Verification Bypass on HTTPS Redirect via Proxy (high 8.7)
- [CVE-2026-22776](https://insights.sbomify.com/CVE-2026-22776/): cpp-httplib vulnerable to a denial of service (DOS) using a zip bomb (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-0825 and fix it if it is affected.

What it is: CVE-2025-0825 is a medium-severity vulnerability in yhirose:cpp-httplib, published on 4 Feb 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2025-0825 in the wild and no public exploit code.

Affected product: yhirose:cpp-httplib. 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-2025-0825/ (Markdown: https://insights.sbomify.com/CVE-2025-0825/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-0825
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-0825
- OSV: https://osv.dev/vulnerability/CVE-2025-0825

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-0825/
Summaries are generated and may contain mistakes; the official description above is the record.