CVE-2022-40735: The Diffie-Hellman Key Agreement Protocol allows use of long exponents that arguably make certain calculations

This month

HIGH 7.5REMOTEMITIGATE

CVE-2022-40735 is a high-severity flaw (CVSS 7.5) affecting diffie-hellman key exchange. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Diffie-Hellman Key Agreement Protocol allows use of long exponents that arguably make certain calculations unnecessarily expensive, because the 1996 van Oorschot and Wiener paper found that "(appropriately) short exponents" can be used when there are adequate subgroup constraints, and these short exponents can lead to less expensive calculations than for long exponents. This issue is different from CVE-2002-20001 because it is based on an obs

Why this priority

High severity
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.6% (top 14%)
CISA exploited list	No
Weakness	CWE-400
Published	2022-11-14
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: diffie-hellman key exchange project

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

Am I affected?

Timeline

2022-11-14 23:15 UTCPublished CVE record published
2026-06-17 05:01 UTCUpdated Record last modified

diffie-hellman key exchange project diffie-hellman key exchange MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy diffie-hellman-key-exchange || rpm -q diffie-hellman-key-exchange || diffie-hellman-key-exchange --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

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-2022-40735?

diffie-hellman key exchange: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2022-40735 being exploited?

CVE-2022-40735 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-2022-40735 affect?

CVE-2022-40735 affects diffie-hellman key exchange. Severity is high (CVSS 7.5). The Diffie-Hellman Key Agreement Protocol allows use of long exponents that arguably make certain calculations unnecessarily expensive, because the 1996 van Oorschot and Wiener paper found that "(appropriately) short exponents" can be used

How urgent is CVE-2022-40735?

Priority 53/100. High severity; Remotely exploitable, no login, no user action

References

← Back to latest CVEs