CVE-2026-63076
CVSS v3
7.5
HIGH
EPSS Score
1.6 %
exploit probability, as of 2026-10-19
CISA KEV
No
known exploited
Exploitation
—
SSVC status
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Affected and fixed versions
Packages from OSV.dev and products from the vendors' CSAF advisories.
version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.
Packages
- opensslAlmaLinux:10all versions · fixed in 1:3.5.8-1.el10_2.alma.1and 3 other packages
- opensslAlmaLinux:9all versions · fixed in 1:3.5.8-1.el9_8and 3 other packages
Vendor advisories
openssl: invalid pointer dereference in CMP server via crafted protectionAlg
edk2-aarch64 as a component of Red Hat Enterprise Linux 10 · edk2-ovmf as a component of Red Hat Enterprise Linux 10 · edk2-tools as a component of Red Hat Enterprise Linux 10
Red Hat Security Advisory: Cost Management Metrics Operator Update
Red Hat Security Advisory: Red Hat Cost Management On-Premise container image update
Red Hat Security Advisory: Red Hat Developer Hub 1.10.5 release.
Red Hat Security Advisory: cert-manager Operator for Red Hat OpenShift 1.20.1
Red Hat Security Advisory: cert-manager Operator for Red Hat OpenShift 1.20.1
10 more advisories
Description
Issue summary: OpenSSL CMP password based protection verification only checks whether the protectionAlg parameter was not NULL and not its ASN.1 type, before treating it as a PBMParameter. A crafted message can contain a parameter of a different type, which is then dereferenced as an invalid pointer. Impact summary: A remote, unauthenticated attacker can crash an application acting as a CMP server that accepts PBM-protected messages, or a CMP client talking to a malicious or intercepted CMP server, resulting in a Denial of Service. CWE: CWE-476: NULL Pointer Dereference Description: When verifying the password-based MAC protection of a CMP message, OpenSSL library reads the protectionAlg algorithm parameter with X509_ALGOR_get0(), which returns both the parameter type and its value pointer. The value is then cast to an ASN1_STRING and treated as the expected PBMParameter after only checking that pointer is not NULL. The parameter type returned by X509_ALGOR_get0() was never consulted. This happens during protection verification, before any MAC is computed, so no knowledge of the PBM shared secret is required; the only precondition is that PBM verification is reachable. On the server side this is reached from OSSL_CMP_SRV_process_request() for any application that stands up a CMP server accepting PBM-protected messages, and on the client side from CMP response validation against a malicious or on-path (MITM) server. The reliable consequence is a denial of service; there is no memory disclosure, no controlled memory write, and no path to code execution. CMP is a specialized feature that an application must explicitly enable. FIPS impact: no As the CMP code lives outside the FIPS module boundary, no FIPS modules are affected by this CVE.
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Published
- 2026-08-25
- Last Modified
- 2026-08-25
Frequently asked questions
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