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-2026-239 Issue summary: Processing some specially crafted ASN.1 object identifiers or data containing them...

Issue summary: Processing some specially crafted ASN.1 object identifiers or data containing them may be very slow. Impact summary: Applications that use OBJobj2txt directly, or use any of the OpenSSL subsystems OCSP, PKCS7/SMIME, CMS, CMP/CRMF or TS with no message size limit may experience...

JLSEC-2026-240 Issue summary: The AES-SIV cipher implementation contains a bug that causes it to ignore empty...

Issue summary: The AES-SIV cipher implementation contains a bug that causes it to ignore empty associated data entries which are unauthenticated as a consequence. Impact summary: Applications that use the AES-SIV algorithm and want to authenticate empty data entries as associated data can be misl...

JLSEC-2026-231 openssl-src subject to Timing Oracle in RSA Decryption

A timing based side channel exists in the OpenSSL RSA Decryption implementation which could be sufficient to recover a plaintext across a network in a Bleichenbacher style attack. To achieve a successful decryption an attacker would have to be able to send a very large number of trial messages fo...

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

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-2026-228 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-2026-242 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-2026-227 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-2026-261 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-2026-216 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-2026-225 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-2026-234 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-2026-230 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-2026-233 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-2026-221 Integer Overflow in openssl-src

Calls to EVPCipherUpdate, EVPEncryptUpdate and EVPDecryptUpdate may overflow the output length argument in some cases where the input length is close to the maximum permissable length for an integer on the platform. In such cases the return value from the function call will be 1 indicating succes...

CLSA-2026-1777297012 openssl: Fix of 3 CVEs

CVE-2026-28388: fix NULL dereference in checkdeltabase when a Delta CRL lacks the CRL Number extension - CVE-2026-28389: fix NULL dereference in dh/ecdhcmssetsharedinfo when KeyEncryptionAlgorithmIdentifier has no parameters field - CVE-2026-28390: fix NULL dereference in rsacmsdecrypt when the...

pyOpenSSL: DTLS cookie callback buffer overflow

A flaw was found in pyOpenSSL. The setcookiegeneratecallback callback function can be used to generate DTLS cookies. When the callback returns a cookie string or byte sequence longer than 256 bytes, a buffer overflow can be triggered due to a missing bounds checking before copying the data to a...