OESA-2026-2190

OpenSSL is a robust, commercial-grade, and full-featured toolkit for the Transport Layer Security (TLS) and Secure Sockets Layer (SSL) protocols.

Security Fix(es):

Issue summary: An invalid or NULL pointer dereference can happen in an application processing a malformed PKCS#12 file.

Impact summary: An application processing a malformed PKCS#12 file can be caused to dereference an invalid or NULL pointer on memory read, resulting in a Denial of Service.

A type confusion vulnerability exists in PKCS#12 parsing code where an ASN1_TYPE union member is accessed without first validating the type, causing an invalid pointer read.

The location is constrained to a 1-byte address space, meaning any attempted pointer manipulation can only target addresses between 0x00 and 0xFF. This range corresponds to the zero page, which is unmapped on most modern operating systems and will reliably result in a crash, leading only to a Denial of Service. Exploiting this issue also requires a user or application to process a maliciously crafted PKCS#12 file. It is uncommon to accept untrusted PKCS#12 files in applications as they are usually used to store private keys which are trusted by definition. For these reasons, the issue was assessed as Low severity.

The FIPS modules in 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the PKCS12 implementation is outside the OpenSSL FIPS module boundary.

OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0 and 1.1.1 are vulnerable to this issue.

OpenSSL 1.0.2 is not affected by this issue.(CVE-2026-22795)

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.(CVE-2026-28387)

Issue summary: When a delta CRL that contains a Delta CRL Indicator extension is processed a NULL pointer dereference might happen if the required CRL Number extension is missing.

Impact summary: A NULL pointer dereference can trigger a crash which leads to a Denial of Service for an application.

When CRL processing and delta CRL processing is enabled during X.509 certificate verification, the delta CRL processing does not check whether the CRL Number extension is NULL before dereferencing it. When a malformed delta CRL file is being processed, this parameter can be NULL, causing a NULL pointer dereference.

Exploiting this issue requires the X509VFLAGUSEDELTAS flag to be enabled in the verification context, the certificate being verified to contain a freshestCRL extension or the base CRL to have the EXFLAG_FRESHEST flag set, and an attacker to provide a malformed CRL to an application that processes it.

The vulnerability is limited to Denial of Service and cannot be escalated to achieve code execution or memory disclosure. For that reason the issue was assessed as Low severity according to our Security Policy.

The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.(CVE-2026-28388)

Issue summary: During processing of a crafted CMS EnvelopedData message with KeyAgreeRecipientInfo a NULL pointer dereference can happen.

Impact summary: Applications that process attacker-controlled CMS data may crash before authentication or cryptographic operations occur resulting in Denial of Service.

When a CMS EnvelopedData message that uses KeyAgreeRecipientInfo is processed, the optional parameters field of KeyEncryptionAlgorithmIdentifier is examined without checking for its presence. This results in a NULL pointer dereference if the field is missing.

Applications and services that call CMS_decrypt() on untrusted input (e.g., S/MIME processing or CMS-based protocols) are vulnerable.

The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.(CVE-2026-28389)

Issue summary: During processing of a crafted CMS EnvelopedData message with KeyTransportRecipientInfo a NULL pointer dereference can happen.

Impact summary: Applications that process attacker-controlled CMS data may crash before authentication or cryptographic operations occur resulting in Denial of Service.

When a CMS EnvelopedData message that uses KeyTransportRecipientInfo with RSA-OAEP encryption is processed, the optional parameters field of RSA-OAEP SourceFunc algorithm identifier is examined without checking for its presence. This results in a NULL pointer dereference if the field is missing.

Applications and services that call CMS_decrypt() on untrusted input (e.g., S/MIME processing or CMS-based protocols) are vulnerable.

The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.(CVE-2026-28390)