CVE-2026-72897: Issue summary: A TLS server that calls SSL_set_SSL_CTX() to switch a connection to a different SSL_CTX part wa

Q: How do I fix CVE-2026-72897?

openssl: upgrade to 3.4.8, 3.5.9, 3.6.5, 4.0.3. Exact commands for each OS are on this page.

Q: Is CVE-2026-72897 being exploited?

CVE-2026-72897 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-2026-72897 affect?

CVE-2026-72897 affects openssl. Severity is high (CVSS 7.5). Issue summary: A TLS server that calls SSL_set_SSL_CTX() to switch a connection to a different SSL_CTX part way through a handshake may access memory beyond the end of an internal array if the replacement context knows about more provider s

Q: How urgent is CVE-2026-72897?

Priority 44/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

This month

HIGH 7.5REMOTEWATCHLISTUPGRADE

CVE-2026-72897 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: A TLS server that calls SSL_set_SSL_CTX() to switch a connection to a different SSL_CTX part way through a handshake may access memory beyond the end of an internal array if the replacement context knows about more provider signature algorithms than the context the connection was created from. Applications which never call SSL_set_SSL_CTX() are not affected. Impact summary: A remote peer may be able to cause a small out-of-bounds

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	0.4% (top 67%)
CISA exploited list	No
Weakness	CWE-787
Published	2026-09-29
Last modified	2026-10-08

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

Last updated 2026-10-08 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-29 16:17 UTCPublished CVE record published
2026-10-08 01:19 UTCUpdated Record last modified

openssl openssl UPGRADE

Affected: >= 3.4.0 and < 3.4.8 · >= 3.5.0 and < 3.5.9 · >= 3.6.0 and < 3.6.5 · >= 4.0.0 and < 4.0.3

Fixed in: 3.4.8, 3.5.9, 3.6.5, 4.0.3

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 3.4.8 (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 2023 ALAS: ALAS2023-2026-3227 (important): edk2 2026-10-24

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-2026-72897?

openssl: upgrade to 3.4.8, 3.5.9, 3.6.5, 4.0.3. Exact commands for each OS are on this page.

Is CVE-2026-72897 being exploited?

CVE-2026-72897 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-2026-72897 affect?

CVE-2026-72897 affects openssl. Severity is high (CVSS 7.5). Issue summary: A TLS server that calls SSL_set_SSL_CTX() to switch a connection to a different SSL_CTX part way through a handshake may access memory beyond the end of an internal array if the replacement context knows about more provider s

How urgent is CVE-2026-72897?

Priority 44/100. 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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