OpenSSLFramework / library
CVE-2026-28387
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIssue 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.
In the news
Third-party coverage- OpenSSL 3.6.2 lands with eight CVE fixes - Help Net Security
- Microsoft CVE Summary - Bleeping Computer
Surfaced from public web coverage — external links open in a new tab.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisMemory is used after it has been freed, so its contents — now potentially attacker-controlled — drive the program's behaviour. With careful heap grooming this becomes code execution. The fix requires disciplined ownership of memory and often a targeted rework of the object lifecycle.
General guidance for the use after free class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
OpenSSLFramework / library
>= 1.1.1, < 1.1.1zg>= 3.0.0, < 3.0.20>= 3.3.0, < 3.3.7>= 3.4.0, < 3.4.5>= 3.5.0, < 3.5.6>= 3.6.0, < 3.6.2CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped1.1.1zg3.0.203.3.7
OpenSSL 1.1.1zg / 3.0.20 / 3.3.7 / 3.4.5 (or later in respective branches)
- 1. Identify the currently installed OpenSSL version by running 'openssl version' or checking your system's package manager.
- 2. Determine which version branch you are using (1.1.1, 3.0.x, 3.3.x, or 3.4.x).
- 3. For OpenSSL 1.1.1: Upgrade to version 1.1.1zg or later (e.g., 1.1.1zh or latest 1.1.1 release).
- 4. For OpenSSL 3.0.x: Upgrade to version 3.0.20 or later (e.g., 3.0.21 or latest 3.0 release).
- 5. For OpenSSL 3.3.x: Upgrade to version 3.3.7 or later (e.g., 3.3.8 or latest 3.3 release).
- 6. For OpenSSL 3.4.x: Upgrade to version 3.4.5 or later (e.g., 3.4.6 or latest 3.4 release).
- 7. Use your system's package manager (apt, yum, dnf, brew, etc.) or compile from source to obtain the fixed version.
- 8. Verify the upgrade was successful by running 'openssl version' and confirming the version number is at or above the appropriate fixed release for your branch.
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-28387 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-28387 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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