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CVE-2026-63073

CVE Details​

Visit the official vulnerability details page for CVE-2026-63073 to learn more.

Initial Publication​

08/25/2026

Last Update​

09/11/2026

Third Party Dependency​

libcrypto3

NIST CVE Summary​

Issue summary: OpenSSL CMP response validation passed an unexpected response sender distinguished name directly as the format string to `ERR_raise_data()`.

Impact summary: A malicious or intercepted CMP endpoint can crash a CMP client that enforces an expected sender or uses a pinned server certificate whose subject becomes the default expected sender.

CWE: CWE-134 (Use of Externally-Controlled Format String)

Description: When validating a received CMP message, ossl_cmp_msg_check_update() converts the peer-supplied sender distinguished name with X509_NAME_oneline() and passes it directly as the format argument to ERR_raise_data(). Percent characters survive the conversion, so a sender DN such as "CN=%s%n" reaches BIO_vsnprintf() as an attacker-controlled format string with no matching variadic arguments. This path is only reached when the caller configures an expected sender or pins a server certificate, which is the normal configuration for a CMP client validating server responses.

Since the attacker controls the format string but none of the variadic arguments, such specifiers as %s and %n dereference or write through unrelated stack contents and crash the client. The reliable consequence is a denial of service, when the response comes from a malicious or intercepted CMP endpoint. There is no controlled memory write, arbitrary-address read, or reliable path to remote code execution.

FIPS impact: no

No FIPS modules are affected by this issue, as the CMP protocol implementation is outside the OpenSSL FIPS module boundary.

CVE Severity​

9.8

Our Official Summary​

Investigation is ongoing to determine how this vulnerability affects our products.

Status​

Analyzed

Affected Products & Versions​

VersionPaletteAIPaletteAI VerteX
1.4.0⚠️ Impacted⚠️ Impacted
1.3.2⚠️ Impacted⚠️ Impacted
1.2.2⚠️ Impacted⚠️ Impacted

Revision History​

No revisions available.