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🛡️ CVE-2026-28387 — openssl

🟠 CVSS 8.1 — High ✅ No Known Exploit CWE-416 NVD
8.1
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Issue summary: An uncommon configuration of clients performing DANE TLSA-based

server authentication, when paired with uncommon server DANE TLSA records, may

result in a use-after-free and/or double-free on the client side.

Impact summary: A use after free can have a range of potential consequences

such as the corruption of valid data, crashes or execution of arbitrary code.

However, the issue only affects clients that make use of TLSA records with both

the PKIX-TA(0/PKIX-EE(1) certificate usages and the DANE-TA(2) certificate

usage.

By far the most common deployment of DANE is in SMTP MTAs for which RFC7672

recommends that clients treat as 'unusable' any TLSA records that have the PKIX

certificate usages. These SMTP (or other similar) clients are not vulnerable

to this issue. Conversely, any clients that support only the PKIX usages, and

ignore the DANE-TA(2) usage are also not vulnerable.

The client would also need to be communicating with a server that publishes a

TLSA RRset with both types of TLSA records.

No FIPS modules are affected by this issue, the problem code is outside the

FIPS module boundary.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is high, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: High — the attacker first has to win a race, learn a secret or otherwise prepare the target.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: High — total loss, or loss the attacker controls.

Weakness class

CVE-2026-28387 is classified as CWE-416: Use After Free. Memory is used after being released, so its contents may already belong to something else.

Affected software

CVE-2026-28387 is recorded against 1 package.

  • openssl (from 3.6.0 up to 3.6.2)

Timeline and source

Published on 7 April 2026 and last revised on 24 July 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

github.com
github.com
github.com
github.com
github.com
openssl-library.org
cert-portal.siemens.com
cert-portal.siemens.com

Other advisories for this package

openssl has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-416: Use After Free) in other software:

CVE-2026-28387 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity HIGH
CVSS Score 8.1
CVSS Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE CWE-416
Public Exploit ✅ No
Source NVD
Published 2026-04-07
Updated 2026-08-20
Modified 2026-07-24

Affected Packages

Software From version Fixed in
openssl 3.6.0 3.6.2

Site Security Check

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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