High 8.1Published Apr 7, 2026

CVE-2026-28387Potential Use-after-free in DANE Client Code

Updated under an hour ago (2026-10-19 07:23 UTC)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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.

CVSS: 8.1 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-416
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: openssl
NVD analysis: Modified
Record last updated: Oct 15, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

OpenSSL OpenSSL openssl:openssl (from the name)	from 3.6.0 before 3.6.2; from 3.5.0 before 3.5.6; from 3.4.0 before 3.4.5; from 3.3.0 before 3.3.7; from 3.0.0 before 3.0.20; from 1.1.1 before 1.1.1zg	CNA record
Siemens SIMATIC CN 4100 siemens:simatic_cn_4100 (from the name)	before V5.0	CISA ADP
Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem siemens:simatic_s7_1500_tm_mfp_gnu_linux_subsystem (from the name)	all versions	CISA ADP
openssl openssl openssl:openssl	from 1.1.1 before 1.1.1zg; from 3.0.0 before 3.0.20; from 3.3.0 before 3.3.7; from 3.4.0 before 3.4.5; from 3.5.0 before 3.5.6; from 3.6.0 before 3.6.2	NVD

References

https://openssl-library.org/news/secadv/20260407.txtvendor-advisory
https://github.com/openssl/openssl/commit/258a8f63b26995ba357f4326da00e19e29c6acbepatch
https://github.com/openssl/openssl/commit/444958deaf450aea819171f97ae69eaedede42c3patch
https://github.com/openssl/openssl/commit/07e727d304746edb49a98ee8f6ab00256e1f012bpatch
https://github.com/openssl/openssl/commit/7a4e08cee62a728d32e60b0de89e6764339df0a7patch
https://github.com/openssl/openssl/commit/ec03fa050b3346997ed9c5fef3d0e16ad7db8177patch
https://cert-portal.siemens.com/productcert/html/ssa-032379.html
https://cert-portal.siemens.com/productcert/html/ssa-265688.html

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.