Openssl: >> Openssl Security Vulnerabilities
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.
CVSS Score
7.5
EPSS Score
0.0
Published
2026-04-07
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.
CVSS Score
7.5
EPSS Score
0.0
Published
2026-04-07
Issue summary: Converting an excessively large OCTET STRING value to
a hexadecimal string leads to a heap buffer overflow on 32 bit platforms.
Impact summary: A heap buffer overflow may lead to a crash or possibly
an attacker controlled code execution or other undefined behavior.
If an attacker can supply a crafted X.509 certificate with an excessively
large OCTET STRING value in extensions such as the Subject Key Identifier
(SKID) or Authority Key Identifier (AKID) which are being converted to hex,
the size of the buffer needed for the result is calculated as multiplication
of the input length by 3. On 32 bit platforms, this multiplication may overflow
resulting in the allocation of a smaller buffer and a heap buffer overflow.
Applications and services that print or log contents of untrusted X.509
certificates are vulnerable to this issue. As the certificates would have
to have sizes of over 1 Gigabyte, printing or logging such certificates
is a fairly unlikely operation and only 32 bit platforms are affected,
this issue was assigned Low severity.
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.
CVSS Score
9.8
EPSS Score
0.0
Published
2026-04-07
Issue summary: Applications using RSASVE key encapsulation to establish
a secret encryption key can send contents of an uninitialized memory buffer to
a malicious peer.
Impact summary: The uninitialized buffer might contain sensitive data from the
previous execution of the application process which leads to sensitive data
leakage to an attacker.
RSA_public_encrypt() returns the number of bytes written on success and -1
on error. The affected code tests only whether the return value is non-zero.
As a result, if RSA encryption fails, encapsulation can still return success to
the caller, set the output lengths, and leave the caller to use the contents of
the ciphertext buffer as if a valid KEM ciphertext had been produced.
If applications use EVP_PKEY_encapsulate() with RSA/RSASVE on an
attacker-supplied invalid RSA public key without first validating that key,
then this may cause stale or uninitialized contents of the caller-provided
ciphertext buffer to be disclosed to the attacker in place of the KEM
ciphertext.
As a workaround calling EVP_PKEY_public_check() or
EVP_PKEY_public_check_quick() before EVP_PKEY_encapsulate() will mitigate
the issue.
The FIPS modules in 3.6, 3.5, 3.4, 3.3, 3.1 and 3.0 are affected by this issue.
CVSS Score
7.5
EPSS Score
0.0
Published
2026-04-07
Issue summary: Applications using AES-CFB128 encryption or decryption on
systems with AVX-512 and VAES support can trigger an out-of-bounds read
of up to 15 bytes when processing partial cipher blocks.
Impact summary: This out-of-bounds read may trigger a crash which leads to
Denial of Service for an application if the input buffer ends at a memory
page boundary and the following page is unmapped. There is no information
disclosure as the over-read bytes are not written to output.
The vulnerable code path is only reached when processing partial blocks
(when a previous call left an incomplete block and the current call provides
fewer bytes than needed to complete it). Additionally, the input buffer
must be positioned at a page boundary with the following page unmapped.
CFB mode is not used in TLS/DTLS protocols, which use CBC, GCM, CCM, or
ChaCha20-Poly1305 instead. For these reasons the issue was assessed as
Low severity according to our Security Policy.
Only x86-64 systems with AVX-512 and VAES instruction support are affected.
Other architectures and systems without VAES support use different code
paths that are not affected.
OpenSSL FIPS module in 3.6 version is affected by this issue.
CVSS Score
7.5
EPSS Score
0.001
Published
2026-04-07
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.
CVSS Score
8.1
EPSS Score
0.0
Published
2026-04-07
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 X509_V_FLAG_USE_DELTAS 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.
CVSS Score
7.5
EPSS Score
0.0
Published
2026-04-07
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.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-27
Issue summary: A type confusion vulnerability exists in the signature
verification of signed PKCS#7 data where an ASN1_TYPE union member is
accessed without first validating the type, causing an invalid or NULL
pointer dereference when processing malformed PKCS#7 data.
Impact summary: An application performing signature verification of PKCS#7
data or calling directly the PKCS7_digest_from_attributes() function can be
caused to dereference an invalid or NULL pointer when reading, resulting in
a Denial of Service.
The function PKCS7_digest_from_attributes() accesses the message digest attribute
value without validating its type. When the type is not V_ASN1_OCTET_STRING,
this results in accessing invalid memory through the ASN1_TYPE union, causing
a crash.
Exploiting this vulnerability requires an attacker to provide a malformed
signed PKCS#7 to an application that verifies it. The impact of the
exploit is just a Denial of Service, the PKCS7 API is legacy and applications
should be using the CMS API instead. 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 PKCS#7 parsing implementation is outside the OpenSSL FIPS module
boundary.
OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0, 1.1.1 and 1.0.2 are vulnerable to this issue.
CVSS Score
5.3
EPSS Score
0.001
Published
2026-01-27
Issue summary: Calling PKCS12_get_friendlyname() function on a maliciously
crafted PKCS#12 file with a BMPString (UTF-16BE) friendly name containing
non-ASCII BMP code point can trigger a one byte write before the allocated
buffer.
Impact summary: The out-of-bounds write can cause a memory corruption
which can have various consequences including a Denial of Service.
The OPENSSL_uni2utf8() function performs a two-pass conversion of a PKCS#12
BMPString (UTF-16BE) to UTF-8. In the second pass, when emitting UTF-8 bytes,
the helper function bmp_to_utf8() incorrectly forwards the remaining UTF-16
source byte count as the destination buffer capacity to UTF8_putc(). For BMP
code points above U+07FF, UTF-8 requires three bytes, but the forwarded
capacity can be just two bytes. UTF8_putc() then returns -1, and this negative
value is added to the output length without validation, causing the
length to become negative. The subsequent trailing NUL byte is then written
at a negative offset, causing write outside of heap allocated buffer.
The vulnerability is reachable via the public PKCS12_get_friendlyname() API
when parsing attacker-controlled PKCS#12 files. While PKCS12_parse() uses a
different code path that avoids this issue, PKCS12_get_friendlyname() directly
invokes the vulnerable function. Exploitation requires an attacker to provide
a malicious PKCS#12 file to be parsed by the application and the attacker
can just trigger a one zero byte write before the allocated buffer.
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 PKCS#12 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.
CVSS Score
7.4
EPSS Score
0.001
Published
2026-01-27
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