# CVE-2026-32627: cpp-httplib has a Silent TLS Certificate Verification Bypass on HTTPS Redirect via Proxy

> Attackers can intercept HTTPS traffic by exploiting a TLS verification bypass during redirects in cpp-httplib clients using proxies.

- **Severity:** High 8.7 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Mar 2026
- **Updated:** 16 Mar 2026
- **Also known as:** DEBIAN-CVE-2026-32627, GHSA-c3h8-fqq4-xm4g, UBUNTU-CVE-2026-32627

## What is CVE-2026-32627?

CVE-2026-32627 is a high-severity vulnerability in yhirose cpp-httplib, published on 13 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.37.2, when a cpp-httplib client is configured with a proxy and set_follow_location(true), any HTTPS redirect it follows will have TLS certificate and hostname verification silently disabled on the new connection. The client will accept any certificate presented by the redirect target — expired, self-signed, or forged — without raising an error or notifying the application. A network attacker in a position to return a redirect response can fully intercept the follow-up HTTPS connection, including any credentials or session tokens in flight. This vulnerability is fixed in 0.37.2.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2026-32627?

It affects 1 product.


Products: Yhirose Cpp-Httplib.

## How do I fix CVE-2026-32627?

Upgrade to a fixed version.

## Is CVE-2026-32627 being exploited?

There is no known exploitation of CVE-2026-32627 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-2026-22776](https://insights.sbomify.com/CVE-2026-22776/): cpp-httplib vulnerable to a denial of service (DOS) using a zip bomb (high 8.7)
- [CVE-2026-21428](https://insights.sbomify.com/CVE-2026-21428/): cpp-httplib has CRLF injection in http headers (high 7.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-32627 and fix it if it is affected.

What it is: CVE-2026-32627 is a high-severity vulnerability in yhirose cpp-httplib, published on 13 Mar 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-2026-32627 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-2026-32627/ (Markdown: https://insights.sbomify.com/CVE-2026-32627/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-32627
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-32627
- OSV: https://osv.dev/vulnerability/CVE-2026-32627

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-32627/
Summaries are generated and may contain mistakes; the official description above is the record.