CVE-2023-5678: Issue summary: Generating excessively long X9.42 DH keys or checking excessively long X9.42 DH keys or paramet

Q: How do I fix CVE-2023-5678?

openssl: upgrade to 1.0.2zj, 1.1.1x, 3.0.13, 3.1.5. Exact commands for each OS are on this page.

Q: Is CVE-2023-5678 being exploited?

CVE-2023-5678 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-2023-5678 affect?

CVE-2023-5678 affects openssl. Severity is medium (CVSS 5.3). Issue summary: Generating excessively long X9.42 DH keys or checking excessively long X9.42 DH keys or parameters may be very slow. Impact summary: Applications that use the functions DH_generate_key() to generate an X9.42 DH key may exper

Q: How urgent is CVE-2023-5678?

Priority 51/100. EPSS top 9%: very likely to be exploited; Remotely exploitable, no login, no user action; On your watchlist

This month

MEDIUM 5.3REMOTEWATCHLISTUPGRADE

CVE-2023-5678 is a medium-severity flaw (CVSS 5.3) affecting openssl. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Issue summary: Generating excessively long X9.42 DH keys or checking excessively long X9.42 DH keys or parameters may be very slow. Impact summary: Applications that use the functions DH_generate_key() to generate an X9.42 DH key may experience long delays. Likewise, applications that use DH_check_pub_key(), DH_check_pub_key_ex() or EVP_PKEY_public_check() to check an X9.42 DH key or X9.42 DH parameters may experience long delays. Where the key

Why this priority

EPSS top 9%: very likely to be exploited
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	4.5% (top 9%)
CISA exploited list	No
Weakness	CWE-606, CWE-754
Published	2023-11-06
Last modified	2026-10-14

Publisher (CNA): OpenSSL Software Foundation · Vendor: openssl

Last updated 2026-10-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-11-06 16:15 UTCPublished CVE record published
2026-10-14 22:17 UTCUpdated Record last modified

openssl openssl UPGRADE

Affected: >= 1.0.2 and < 1.0.2zj · >= 1.1.1 and < 1.1.1x · >= 3.0.0 and < 3.0.13 · >= 3.1.0 and < 3.1.5

Fixed in: 1.0.2zj, 1.1.1x, 3.0.13, 3.1.5

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 1.0.2zj (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade openssl

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-2023-5678?

openssl: upgrade to 1.0.2zj, 1.1.1x, 3.0.13, 3.1.5. Exact commands for each OS are on this page.

Is CVE-2023-5678 being exploited?

CVE-2023-5678 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-2023-5678 affect?

CVE-2023-5678 affects openssl. Severity is medium (CVSS 5.3). Issue summary: Generating excessively long X9.42 DH keys or checking excessively long X9.42 DH keys or parameters may be very slow. Impact summary: Applications that use the functions DH_generate_key() to generate an X9.42 DH key may exper

How urgent is CVE-2023-5678?

Priority 51/100. EPSS top 9%: very likely to be exploited; Remotely exploitable, no login, no user action; On your watchlist

Software pages

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References

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