JLSEC-2026-224 SM2 Decryption Buffer Overflow

In order to decrypt SM2 encrypted data an application is expected to call the API function EVPPKEYdecrypt. Typically an application will call this function twice. The first time, on entry, the "out" parameter can be NULL and, on exit, the "outlen" parameter is populated with the buffer size...

JLSEC-2026-225 Read buffer overruns processing ASN.1 strings

ASN.1 strings are represented internally within OpenSSL as an ASN1STRING structure which contains a buffer holding the string data and a field holding the buffer length. This contrasts with normal C strings which are repesented as a buffer for the string data which is terminated with a NUL 0 byte...

JLSEC-2026-227 openssl-src's infinite loop in `BN_mod_sqrt()` reachable when parsing certificates

The BNmodsqrt function, which computes a modular square root, contains a bug that can cause it to loop forever for non-prime moduli. Internally this function is used when parsing certificates that contain elliptic curve public keys in compressed form or explicit elliptic curve parameters with a...

JLSEC-2026-228 The `c_rehash` script does not properly sanitise shell metacharacters to prevent command injection

The crehash script does not properly sanitise shell metacharacters to prevent command injection. This script is distributed by some operating systems in a manner where it is automatically executed. On such operating systems, an attacker could execute arbitrary commands with the privileges of the...

JLSEC-2026-244 Issue summary: Generating excessively long X9.42 DH keys or checking excessively long X9.42 DH keys...

Issue summary: Generating excessively long X9.42 DH keys or checking excessively long X9.42 DH keys or parameters may be very slow. Impact summary: Applications that use the functions DHgeneratekey to generate an X9.42 DH key may experience long delays. Likewise, applications that use...

JLSEC-2026-263 Issue summary: Calling `PKCS12_get_friendlyname()` function on a maliciously crafted PKCS#12 file...

Issue summary: Calling PKCS12getfriendlyname function on a maliciously crafted PKCS12 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...

JLSEC-2026-245 Issue summary: The POLY1305 MAC (message authentication code) implementation contains a bug that...

Issue summary: The POLY1305 MAC message authentication code implementation contains a bug that might corrupt the internal state of applications running on PowerPC CPU based platforms if the CPU provides vector instructions. Impact summary: If an attacker can influence whether the POLY1305 MAC...

JLSEC-2026-251 Issue summary: Calling the OpenSSL API function `SSL_free_buffers` may cause memory to be accessed...

Issue summary: Calling the OpenSSL API function SSLfreebuffers may cause memory to be accessed that was previously freed in some situations 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...

JLSEC-2026-258 Issue summary: The 'openssl dgst' command-line tool silently truncates input data to 16MB when using...

Issue summary: The 'openssl dgst' command-line tool silently truncates input data to 16MB when using one-shot signing algorithms and reports success instead of an error. Impact summary: A user signing or verifying files larger than 16MB with one-shot algorithms such as Ed25519, Ed448, or ML-DSA m...

JLSEC-2026-247 Null pointer dereference in PKCS12 parsing

Issue summary: Processing a maliciously formatted PKCS12 file may lead OpenSSL to crash leading to a potential Denial of Service attack Impact summary: Applications loading files in the PKCS12 format from untrusted sources might terminate abruptly. A file in PKCS12 format can contain certificates...

JLSEC-2026-265 Issue summary: Processing a malformed PKCS#12 file can trigger a NULL pointer dereference in the...

Issue summary: Processing a malformed PKCS12 file can trigger a NULL pointer dereference in the PKCS12itemdecryptd2iex function. Impact summary: A NULL pointer dereference can trigger a crash which leads to Denial of Service for an application processing PKCS12 files. The PKCS12itemdecryptd2iex...

JLSEC-2026-242 Issue summary: The POLY1305 MAC (message authentication code) implementation contains a bug that...

Issue summary: The POLY1305 MAC message authentication code implementation contains a bug that might corrupt the internal state of applications on the Windows 64 platform when running on newer X8664 processors supporting the AVX512-IFMA instructions. Impact summary: If in an application that uses...

JLSEC-2026-277 Issue summary: Applications using RSASVE key encapsulation to establish a secret encryption key can...

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 whi...

JLSEC-2026-264 Issue summary: A type confusion vulnerability exists in the TimeStamp Response verification code...

Issue summary: A type confusion vulnerability exists in the TimeStamp Response verification code where an ASN1TYPE union member is accessed without first validating the type, causing an invalid or NULL pointer dereference when processing a malformed TimeStamp Response file. Impact summary: An...

JLSEC-2026-236 Applications that use a non-default option when verifying certificates may be vulnerable to an...

Applications that use a non-default option when verifying certificates may be vulnerable to an attack from a malicious CA to circumvent certain checks. Invalid certificate policies in leaf certificates are silently ignored by OpenSSL and other certificate policy checks are skipped for that...

JLSEC-2026-256 Issue summary: Parsing CMS AuthEnvelopedData message with maliciously crafted AEAD parameters can...

Issue summary: Parsing CMS AuthEnvelopedData or EnvelopedData message with maliciously crafted AEAD parameters can trigger a stack buffer overflow. Impact summary: A stack buffer overflow may lead to a crash, causing Denial of Service, or potentially remote code execution. When parsing CMS...

JLSEC-2026-259 Issue summary: Use of -addreject option with the openssl x509 application adds a trusted use instead...

Issue summary: Use of -addreject option with the openssl x509 application adds a trusted use instead of a rejected use for a certificate. Impact summary: If a user intends to make a trusted certificate rejected for a particular use it will be instead marked as trusted for that use. A copy & paste...

JLSEC-2026-252 Issue summary: Calling the OpenSSL API function `SSL_select_next_proto` with an empty supported...

Issue summary: Calling the OpenSSL API function SSLselectnextproto with an empty supported client protocols buffer may cause a crash or memory contents to be sent to the peer. Impact summary: A buffer overread can have a range of potential consequences such as unexpected application beahviour or ...

JLSEC-2026-261 Issue summary: Writing large, newline-free data into a BIO chain using the line-buffering filter...

Issue summary: Writing large, newline-free data into a BIO chain using the line-buffering filter where the next BIO performs short writes can trigger a heap-based out-of-bounds write. Impact summary: This out-of-bounds write can cause memory corruption which typically results in a crash, leading ...

JLSEC-2026-215 OpenSSL 1.1.1 introduced a rewritten random number generator (RNG)

OpenSSL 1.1.1 introduced a rewritten random number generator RNG. This was intended to include protection in the event of a fork system call in order to ensure that the parent and child processes did not share the same RNG state. However this protection was not being used in the default case. A...