CVE-2026-28390: Issue summary: During processing of a crafted CMS EnvelopedData message with KeyTransportRecipientInfo a NULL

Q: How do I fix CVE-2026-28390?

openssl: upgrade to 1.0.2zp, 1.1.1zg, 3.0.20, 3.3.7, 3.4.5, 3.5.6, 3.6.2. Exact commands for each OS are on this page.

Q: Is CVE-2026-28390 being exploited?

CVE-2026-28390 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-2026-28390 affect?

CVE-2026-28390 affects openssl. Severity is high (CVSS 7.5). Issue summary: During processing of a crafted CMS EnvelopedData message with KeyTransportRecipientInfo a NULL pointer dereference can happen. Impact summary: Applications that process attacker-controlled CMS data may crash before authentic

Q: How urgent is CVE-2026-28390?

Priority 50/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

This month

HIGH 7.5REMOTEWATCHLISTUPGRADE

CVE-2026-28390 is a high-severity flaw (CVSS 7.5) affecting openssl. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Issue summary: During processing of a crafted CMS EnvelopedData message with KeyTransportRecipientInfo a NULL pointer dereference can happen. Impact summary: Applications that process attacker-controlled CMS data may crash before authentication or cryptographic operations occur resulting in Denial of Service. When a CMS EnvelopedData message that uses KeyTransportRecipientInfo with RSA-OAEP encryption is processed, the optional parameters field

Why this priority

High severity
Remotely exploitable, no login, no user action
On your watchlist

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	0.8% (top 43%)
CISA exploited list	No
Weakness	CWE-476
Published	2026-04-07
Last modified	2026-07-24

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

Last updated 2026-07-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-07 22:16 UTCPublished CVE record published
2026-07-24 23:10 UTCUpdated Record last modified

openssl openssl UPGRADE

Affected: >= 1.0.2 and < 1.0.2zp · >= 1.1.1 and < 1.1.1zg · >= 3.0.0 and < 3.0.20 · >= 3.3.0 and < 3.3.7 · >= 3.4.0 and < 3.4.5 · >= 3.5.0 and < 3.5.6 · >= 3.6.0 and < 3.6.2

Fixed in: 1.0.2zp, 1.1.1zg, 3.0.20, 3.3.7, 3.4.5, 3.5.6, 3.6.2

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 1.0.2zp (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.

Advisories and coverage

Official advisories

AlmaLinux Errata: [ALSA-2026:22313] Moderate: compat-openssl11 security update 2026-06-03

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-2026-28390?

openssl: upgrade to 1.0.2zp, 1.1.1zg, 3.0.20, 3.3.7, 3.4.5, 3.5.6, 3.6.2. Exact commands for each OS are on this page.

Is CVE-2026-28390 being exploited?

CVE-2026-28390 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-2026-28390 affect?

CVE-2026-28390 affects openssl. Severity is high (CVSS 7.5). Issue summary: During processing of a crafted CMS EnvelopedData message with KeyTransportRecipientInfo a NULL pointer dereference can happen. Impact summary: Applications that process attacker-controlled CMS data may crash before authentic

How urgent is CVE-2026-28390?

Priority 50/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

Software pages

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References

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