CVE-2026-63072: Issue summary: OpenSSL CMS decryption sizes the key-unwrap output buffer based on querying the unwrapped key s

Q: How do I fix CVE-2026-63072?

openssl: upgrade to 3.0.22, 3.4.7, 3.5.8, 3.6.4, 4.0.2. Exact commands for each OS are on this page.

Q: Is CVE-2026-63072 being exploited?

CVE-2026-63072 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-2026-63072 affect?

CVE-2026-63072 affects openssl. Severity is high (CVSS 7.5). Issue summary: OpenSSL CMS decryption sizes the key-unwrap output buffer based on querying the unwrapped key size, but the AES-WRAP-PAD unwrap primitive can write and cleanse more bytes than that query reports, causing an 8-byte out-of-boun

Q: How urgent is CVE-2026-63072?

Priority 51/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

This month

HIGH 7.5REMOTEWATCHLISTUPGRADE

CVE-2026-63072 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: OpenSSL CMS decryption sizes the key-unwrap output buffer based on querying the unwrapped key size, but the AES-WRAP-PAD unwrap primitive can write and cleanse more bytes than that query reports, causing an 8-byte out-of-bounds heap write. Impact summary: An attacker who supplies a crafted CMS message can trigger a deterministic 8-byte out-of-bounds heap write when the victim decrypts it with CMS_decrypt(), corrupting the heap and

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	0.9% (top 40%)
CISA exploited list	No
Weakness	CWE-787
Published	2026-08-25
Last modified	2026-09-11

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

Last updated 2026-09-11 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-25 13:19 UTCPublished CVE record published
2026-09-11 21:16 UTCUpdated Record last modified

openssl openssl UPGRADE

Affected: >= 3.0.0 and < 3.0.22 · >= 3.4.0 and < 3.4.7 · >= 3.5.0 and < 3.5.8 · >= 3.6.0 and < 3.6.4 · >= 4.0.0 and < 4.0.2

Fixed in: 3.0.22, 3.4.7, 3.5.8, 3.6.4, 4.0.2

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 3.0.22 (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

Amazon Linux 2 ALAS: ALAS2-2026-3907 (important): openssl11 2026-09-14
Amazon Linux 2 ALAS: ALAS2-2026-3908 (important): edk2 2026-09-14

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-2026-63072?

openssl: upgrade to 3.0.22, 3.4.7, 3.5.8, 3.6.4, 4.0.2. Exact commands for each OS are on this page.

Is CVE-2026-63072 being exploited?

CVE-2026-63072 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-2026-63072 affect?

CVE-2026-63072 affects openssl. Severity is high (CVSS 7.5). Issue summary: OpenSSL CMS decryption sizes the key-unwrap output buffer based on querying the unwrapped key size, but the AES-WRAP-PAD unwrap primitive can write and cleanse more bytes than that query reports, causing an 8-byte out-of-boun

How urgent is CVE-2026-63072?

Priority 51/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

Software pages

OpenSSL vulnerabilities

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References

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