CVE-2024-37880: The Kyber reference implementation before 9b8d306, when compiled by LLVM Clang through 18.x with some common o

Q: How do I fix CVE-2024-37880?

kyber: upgrade to 2024-06-03. Exact commands for each OS are on this page.

Q: Is CVE-2024-37880 being exploited?

CVE-2024-37880 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2024-37880 affect?

CVE-2024-37880 affects kyber. Severity is high (CVSS 7.5). The Kyber reference implementation before 9b8d306, when compiled by LLVM Clang through 18.x with some common optimization options, has a timing side channel that allows attackers to recover an ML-KEM 512 secret key in minutes. This occurs b

Q: How urgent is CVE-2024-37880?

Priority 50/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 7.5REMOTEUPGRADE

CVE-2024-37880 is a high-severity flaw (CVSS 7.5) affecting kyber. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Kyber reference implementation before 9b8d306, when compiled by LLVM Clang through 18.x with some common optimization options, has a timing side channel that allows attackers to recover an ML-KEM 512 secret key in minutes. This occurs because poly_frommsg in poly.c does not prevent Clang from emitting a vulnerable secret-dependent branch.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 47%)
CISA exploited list	No
Weakness	CWE-203
Published	2024-06-10
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: pq-crystals

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2024-06-10 02:15 UTCPublished CVE record published
2026-06-17 07:38 UTCUpdated Record last modified

pq-crystals kyber UPGRADE

Affected: < 2024-06-03

Fixed in: 2024-06-03

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy kyber || rpm -q kyber || kyber --version

2. UPGRADE to 2024-06-03 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade kyber

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade kyber

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2024-37880?

kyber: upgrade to 2024-06-03. Exact commands for each OS are on this page.

Is CVE-2024-37880 being exploited?

CVE-2024-37880 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2024-37880 affect?

CVE-2024-37880 affects kyber. Severity is high (CVSS 7.5). The Kyber reference implementation before 9b8d306, when compiled by LLVM Clang through 18.x with some common optimization options, has a timing side channel that allows attackers to recover an ML-KEM 512 secret key in minutes. This occurs b

How urgent is CVE-2024-37880?

Priority 50/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

References

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