# CVE-2024-36405: Information disclosure in liboqs

> Attackers can recover secret keys via timing side-channels in Kyber implementations compiled with specific Clang optimization flags.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/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:** 10 Jun 2024
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-f2v9-5498-2vpp, openSUSE-SU-2024:14039-1

## What is CVE-2024-36405?

CVE-2024-36405 is a medium-severity vulnerability in open-quantum-safe liboqs, published on 10 Jun 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

liboqs is a C-language cryptographic library that provides implementations of post-quantum cryptography algorithms. A control-flow timing lean has been identified in the reference implementation of the Kyber key encapsulation mechanism when it is compiled with Clang 15-18 for `-Os`, `-O1`, and other compilation options. A proof-of-concept local attack on the reference implementation leaks the entire ML-KEM 512 secret key in ~10 minutes using end-to-end decapsulation timing measurements. The issue has been fixed in version 0.10.1. As a possible workaround, some compiler options may produce vectorized code that does not leak secret information, however relying on these compiler options as a workaround may not be reliable.

Weakness: CWE-385 (Covert Timing Channel), CWE-208 (Observable Timing Discrepancy)

## Which versions are affected by CVE-2024-36405?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `liboqs` | openSUSE:Tumbleweed | All versions | 0.10.1-1.1 |

Products: Openquantumsafe Liboqs.

## How do I fix CVE-2024-36405?

Upgrade to a fixed version.

## Is CVE-2024-36405 being exploited?

There is no known exploitation of CVE-2024-36405 in the wild and no public exploit code.

## Other vulnerabilities in open-quantum-safe liboqs

- [CVE-2024-31510](https://insights.sbomify.com/CVE-2024-31510/): Other in n/a (critical 9.8)
- [CVE-2024-54137](https://insights.sbomify.com/CVE-2024-54137/): liboqs has a correctness error in HQC decapsulation (high 7.4)
- [CVE-2025-52473](https://insights.sbomify.com/CVE-2025-52473/): liboqs secret-dependent branching in HQC reference implementation when compiled with Clang 17-20 (medium 5.9)
- [CVE-2026-44518](https://insights.sbomify.com/CVE-2026-44518/): liboqs: XMSS Buffer Overread Bug (medium 5.3)
- [CVE-2026-46344](https://insights.sbomify.com/CVE-2026-46344/): liboqs: Heap-buffer-overflow in XMSS verification path via OID-controlled parameter mismatch (xmss_commons.c:194) (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-36405 and fix it if it is affected.

What it is: CVE-2024-36405 is a medium-severity vulnerability in open-quantum-safe liboqs, published on 10 Jun 2024. 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-2024-36405 in the wild and no public exploit code.

Affected product: open-quantum-safe liboqs. 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-2024-36405/ (Markdown: https://insights.sbomify.com/CVE-2024-36405/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-36405
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-36405
- OSV: https://osv.dev/vulnerability/CVE-2024-36405

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-36405/
Summaries are generated and may contain mistakes; the official description above is the record.