---
id: CVE-2026-28387
title: |-
  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 summa…
summary: |-
  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 summa…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-416
  - CWE-1341
vendor: openssl
product: openssl
affected:
  - 'openssl >= 1.1.1, < 1.1.1zg'
  - 'openssl >= 3.0.0, < 3.0.20'
  - 'openssl >= 3.3.0, < 3.3.7'
  - 'openssl >= 3.4.0, < 3.4.5'
  - 'openssl >= 3.5.0, < 3.5.6'
  - 'openssl >= 3.6.0, < 3.6.2'
patched:
  - openssl 3.6.2
published: '2026-04-07'
updated: '2026-07-24'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-28387'
references:
  - url: >-
      https://github.com/openssl/openssl/commit/07e727d304746edb49a98ee8f6ab00256e1f012b
    label: openssl-security@openssl.org
  - url: >-
      https://github.com/openssl/openssl/commit/258a8f63b26995ba357f4326da00e19e29c6acbe
    label: openssl-security@openssl.org
  - url: >-
      https://github.com/openssl/openssl/commit/444958deaf450aea819171f97ae69eaedede42c3
    label: openssl-security@openssl.org
  - url: >-
      https://github.com/openssl/openssl/commit/7a4e08cee62a728d32e60b0de89e6764339df0a7
    label: openssl-security@openssl.org
  - url: >-
      https://github.com/openssl/openssl/commit/ec03fa050b3346997ed9c5fef3d0e16ad7db8177
    label: openssl-security@openssl.org
  - url: 'https://openssl-library.org/news/secadv/20260407.txt'
    label: openssl-security@openssl.org
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-032379.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-265688.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28387.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-28387'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2451098'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-28387'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-28387'
  - url: 'https://access.redhat.com/errata/RHSA-2026:7261'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.00943
epssPercentile: 0.59338
ingestedAt: '2026-07-25T23:05:58.103Z'
scores:
  nvd: 8.1
  vendor: 3.7
---

## Overview

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.

## Affected

- `openssl >= 1.1.1, < 1.1.1zg`
- `openssl >= 3.0.0, < 3.0.20`
- `openssl >= 3.3.0, < 3.3.7`
- `openssl >= 3.4.0, < 3.4.5`
- `openssl >= 3.5.0, < 3.5.6`
- `openssl >= 3.6.0, < 3.6.2`

## Remediation

Upgrade past the affected range:

- `openssl 3.6.2`

## Vendor advisories

- **RHSA-2026:7261** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-04-09 · [advisory](https://access.redhat.com/errata/RHSA-2026:7261)
- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat JBoss Core Services, … · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28387.json)