JLSEC-2026-216 There is an overflow bug in the x64_64 Montgomery squaring procedure used in exponentiation with...

There is an overflow bug in the x6464 Montgomery squaring procedure used in exponentiation with 512-bit moduli. No EC algorithms are affected. Analysis suggests that attacks against 2-prime RSA1024, 3-prime RSA1536, and DSA1024 as a result of this defect would be very difficult to perform and are...

JLSEC-2026-246 Issue summary: Checking excessively long invalid RSA public keys may take a long time. Impact...

Issue summary: Checking excessively long invalid RSA public keys may take a long time. Impact summary: Applications that use the function EVPPKEYpubliccheck to check RSA public keys may experience long delays. Where the key that is being checked has been obtained from an untrusted source this may...

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

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-2026-265 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-2026-227 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-2026-277 Issue summary: Applications using RSASVE key encapsulation to establish a secret encryption key...

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-2026-256 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-2026-219 Null pointer deference in openssl-src

Server or client applications that call the SSLcheckchain function during or after a TLS 1.3 handshake may crash due to a NULL pointer dereference as a result of incorrect handling of the "signaturealgorithmscert" TLS extension. The crash occurs if an invalid or unrecognised signature algorithm i...

JLSEC-2026-218 In situations where an attacker receives automated notification of the success or failure of a...

In situations where an attacker receives automated notification of the success or failure of a decryption attempt an attacker, after sending a very large number of messages to be decrypted, can recover a CMS/PKCS7 transported encryption key or decrypt any RSA encrypted message that was encrypted...

JLSEC-2026-223 openssl-src NULL pointer Dereference in signature_algorithms processing

An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signaturealgorithms extension where it was present in the initial ClientHello, but includes a signaturealgorithmscert extension then a NU...

JLSEC-2026-230 AES OCB fails to encrypt some bytes

AES OCB mode for 32-bit x86 platforms using the AES-NI assembly optimised implementation will not encrypt the entirety of the data under some circumstances. This could reveal sixteen bytes of data that was preexisting in the memory that wasn't written. In the special case of "in place" encryption...

JLSEC-2026-234 Vulnerable OpenSSL included in cryptography wheels

There is a type confusion vulnerability relating to X.400 address processing inside an X.509 GeneralName. X.400 addresses were parsed as an ASN1STRING but the public structure definition for GENERALNAME incorrectly specified the type of the x400Address field as ASN1TYPE. This field is subsequentl...

JLSEC-2026-233 openssl-src vulnerable to Use-after-free following `BIO_new_NDEF`

The public API function BIOnewNDEF is a helper function used for streaming ASN.1 data via a BIO. It is primarily used internally to OpenSSL to support the SMIME, CMS and PKCS7 streaming capabilities, but may also be called directly by end user applications. The function receives a BIO from the...

JLSEC-2026-229 In addition to the c_rehash shell command injection identified in CVE-2022-1292, further...

In addition to the crehash shell command injection identified in CVE-2022-1292, further circumstances where the crehash script does not properly sanitise shell metacharacters to prevent command injection were found by code review. When the CVE-2022-1292 was fixed it was not discovered that there...

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-2026-236 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-2026-264 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-2026-217 OpenSSL has internal defaults for a directory tree where it can find a configuration file as well...

OpenSSL has internal defaults for a directory tree where it can find a configuration file as well as certificates used for verification in TLS. This directory is most commonly referred to as OPENSSLDIR, and is configurable with the --prefix / --openssldir configuration options. For OpenSSL versio...

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

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...