# CVE-2026-54919: cpp-httplib: TLS certificate chain verification bypassed for IP-literal hosts on Mbed TLS and wolfSSL backends

> Man-in-the-middle attackers can bypass TLS certificate verification for IP-literal hosts in specific backends, allowing traffic interception and modification.

- **Severity:** High 7.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/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:** No
- **Published:** 10 Jul 2026
- **Updated:** 14 Jul 2026
- **Also known as:** DEBIAN-CVE-2026-54919, GHSA-8ffh-4p95-g3p2, UBUNTU-CVE-2026-54919

## What is CVE-2026-54919?

CVE-2026-54919 is a high-severity vulnerability in yhirose cpp-httplib, published on 10 Jul 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. In affected Mbed TLS backend versions from 0.31.0 through 0.46.1 and wolfSSL backend versions from 0.33.0 through 0.46.1, when cpp-httplib is built with CPPHTTPLIB_MBEDTLS_SUPPORT or CPPHTTPLIB_WOLFSSL_SUPPORT and a client connects to an IP-literal host with server certificate verification enabled, SSLClient and Client in HTTPS mode skip certificate chain validation and WebSocketClient on the Mbed TLS backend skips verification altogether, allowing a man-in-the-middle attacker positioned to intercept traffic to present a crafted certificate and read or modify the traffic. This issue is fixed in version 0.47.0.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2026-54919?

It affects 1 product.


Products: Yhirose Cpp-Httplib.

## How do I fix CVE-2026-54919?

No fix has been published for CVE-2026-54919 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-54919 being exploited?

There is no known exploitation of CVE-2026-54919 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-2026-54919 and fix it if it is affected.

What it is: CVE-2026-54919 is a high-severity vulnerability in yhirose cpp-httplib, published on 10 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-2026-54919 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-2026-54919/ (Markdown: https://insights.sbomify.com/CVE-2026-54919/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-54919
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-54919
- OSV: https://osv.dev/vulnerability/CVE-2026-54919

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-54919/
Summaries are generated and may contain mistakes; the official description above is the record.