DEBIAN-CVE-2026-63073
- Source
- https://security-tracker.debian.org/tracker/CVE-2026-63073
- Import Source
- https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-63073.json
- JSON Data
- https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-63073
- Upstream
- Published
- 2026-08-25T13:19:26Z
- Modified
- 2026-09-13T16:00:06Z
- Severity
-
- 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
- Summary
- [none]
- Details
-
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. - References
Affected packages
Debian:13 / openssl
Package
- Name
- openssl
- Purl
- pkg:deb/debian/openssl?arch=source&distro=trixie
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affectedFixed3.5.7-1~deb13u2
Debian:14 / openssl
Package
- Name
- openssl
- Purl
- pkg:deb/debian/openssl?arch=source&distro=forky
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affectedFixed3.6.4-1