CVE-2026-28387
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 3.0.19-1~deb12u2 |
| debian | bullseye | affected | |
| debian | forky | fixed | 3.6.2-1 |
| debian | sid | fixed | 3.6.2-1 |
| debian | trixie | fixed | 3.5.5-1~deb13u2 |
References
- https://github.com/openssl/openssl/commit/07e727d304746edb49a98ee8f6ab00256e1f012b
- https://github.com/openssl/openssl/commit/258a8f63b26995ba357f4326da00e19e29c6acbe
- https://github.com/openssl/openssl/commit/444958deaf450aea819171f97ae69eaedede42c3
- https://github.com/openssl/openssl/commit/7a4e08cee62a728d32e60b0de89e6764339df0a7
- https://github.com/openssl/openssl/commit/ec03fa050b3346997ed9c5fef3d0e16ad7db8177
- https://openssl-library.org/news/secadv/20260407.txt
- https://cert-portal.siemens.com/productcert/html/ssa-032379.html
- https://cert-portal.siemens.com/productcert/html/ssa-265688.html
- https://www.suse.com/security/cve/CVE-2026-28387.html
- https://security-tracker.debian.org/tracker/CVE-2026-28387
CWEs
CWE-416
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.