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24Track

Potential Use-after-free in DANE Client Code

OpenSSL · CVE-2026-28387
0 news outlets0 CERTs and agencies0 researchers

Assessment: Track

SSVC decision points: exploitation none, automatable no, technical impact total, deployment high.

What is it?

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.

Evidence

No coverage recorded yet.

Exploitation

  • Public proof of concept
  • Exploited in the wild
  • Listed as known exploited
CVSS
8.1
EPSS
0.7%
First seen
2 d ago
Status
corroborated

All OpenSSL vulnerabilities