JLSEC-2026-691 A stack buffer overflow vulnerability exists in wolfSSL's PKCS7 SignedData encoding functionality

A stack buffer overflow vulnerability exists in wolfSSL's PKCS7 SignedData encoding functionality. In wcPKCS7BuildSignedAttributes, when adding custom signed attributes, the code passes an incorrect capacity value esd-signedAttribsCount to EncodeAttributes instead of the remaining available space...

JLSEC-2026-674

In wolfSSL before 5.5.2, if callback functions are enabled via the WOLFSSLCALLBACKS flag, then a malicious TLS 1.3 client or network attacker can trigger a buffer over-read on the heap of 5 bytes. WOLFSSLCALLBACKS is only intended for debugging...

JLSEC-2026-688 Multiple constant-time implementations in wolfSSL before version 5.8.4 may be transformed into...

Multiple constant-time implementations in wolfSSL before version 5.8.4 may be transformed into non-constant-time binary by LLVM optimizations, which can potentially result in observable timing discrepancies and lead to information disclosure through timing side-channel attacks...

JLSEC-2026-754 The PKCS#7 decode path ignores the caller-supplied output buffer size (outputSz), allowing decoded...

The PKCS7 decode path ignores the caller-supplied output buffer size outputSz, allowing decoded content to be written past the bounds of the provided buffer. This affects wolfSSL 5.9.0 and earlier and was fixed in the 5.9.1 release...

JLSEC-2026-758 iPAddress name constraints bypass when `WOLFSSL_IP_ALT_NAME` is not defined

iPAddress name constraints bypass when WOLFSSLIPALTNAME is not defined. IP address name constraints are not enforced in that configuration, allowing a certificate to bypass an issuing CA's IP address constraints...

JLSEC-2026-753 A heap buffer overflow could occur in the DTLS 1.3 ACK serialization path before the connecting peer...

A heap buffer overflow could occur in the DTLS 1.3 ACK serialization path before the connecting peer is authenticated. The buffer overflow was due to an integer truncation when computing the length of the ACK record-number list, causing an undersized buffer to be allocated and then overrun. This...

JLSEC-2026-712

1-byte OOB heap read in wcPKCS7DecodeEnvelopedData via zero-length encrypted content. A vulnerability existed in wolfSSL 5.8.4 and earlier, where a 1-byte out-of-bounds heap read in wcPKCS7DecodeEnvelopedData could be triggered by a crafted CMS EnvelopedData message with zero-length encrypted...

JLSEC-2026-678 In wolfSSL prior to 5.6.6, if callback functions are enabled (via the `WOLFSSL_CALLBACKS` flag),...

In wolfSSL prior to 5.6.6, if callback functions are enabled via the WOLFSSLCALLBACKS flag, then a malicious TLS client or network attacker can trigger a buffer over-read on the heap of 5 bytes WOLFSSLCALLBACKS is only intended for debugging...

JLSEC-2026-669

In wolfSSL before 5.2.0, certificate validation may be bypassed during attempted authentication by a TLS 1.3 client to a TLS 1.3 server. This occurs when the sigalgo field differs between the certificateverify message and the certificate message...

JLSEC-2026-673

In wolfSSL before 5.5.1, malicious clients can cause a buffer overflow during a TLS 1.3 handshake. This occurs when an attacker supposedly resumes a previous TLS session. During the resumption Client Hello a Hello Retry Request must be triggered. Both Client Hellos are required to contain a list ...

JLSEC-2026-685 In function MatchDomainName(), input param str is treated as a NULL terminated string despite being...

In function MatchDomainName, input param str is treated as a NULL terminated string despite being user provided and unchecked. Specifically, the function X509checkhost takes in a pointer and length to check against, with no requirements that it be NULL terminated. If a caller was attempting to do...

JLSEC-2026-681 The side-channel protected T-Table implementation in wolfSSL up to version 5.6.5 protects against a...

The side-channel protected T-Table implementation in wolfSSL up to version 5.6.5 protects against a side-channel attacker with cache-line resolution. In a controlled environment such as Intel SGX, an attacker can gain a per instruction sub-cache-line resolution allowing them to break the...

JLSEC-2026-702 A heap-buffer-overflow vulnerability exists in wolfSSL's `wolfSSL_d2i_SSL_SESSION()` function

A heap-buffer-overflow vulnerability exists in wolfSSL's wolfSSLd2iSSLSESSION function. When deserializing session data with SESSIONCERTS enabled, certificate and session id lengths are read from an untrusted input without bounds validation, allowing an attacker to overflow fixed-size buffers and...

JLSEC-2026-741 Integer underflow in wolfSSL packet sniffer <= 5.9.0 allows an attacker to cause a program crash in...

Integer underflow in wolfSSL packet sniffer = 5.9.0 allows an attacker to cause a program crash in the AEAD decryption path by injecting a TLS record shorter than the explicit IV plus authentication tag into traffic inspected by sslDecodePacket. The underflow wraps a 16-bit length to a large valu...

JLSEC-2026-724 X.509 date buffer overflow in `wolfSSL_X509_notAfter` / `wolfSSL_X509_notBefore`

X.509 date buffer overflow in wolfSSLX509notAfter / wolfSSLX509notBefore. A buffer overflow may occur when parsing date fields from a crafted X.509 certificate via the compatibility layer API. This is only triggered when calling these two APIs directly from an application, and does not affect TLS...

PT-2026-64466

wolfSSL 5.8.4 on RISC-V RV32I architectures lacks a constant-time software implementation for 64-bit multiplication. The compiler-inserted muldi3 subroutine executes in variable time based on operand values. This affects multiple SP math functions sp 256 mul 9, sp 256 sqr 9, etc., leading to a...

PT-2026-64455

wolfSSL through 5.0.0 allows an attacker to cause a denial of service and infinite loop in the client component by sending crafted traffic from a Machine-in-the-Middle MITM position. The root cause is that the client module accepts TLS messages that normally are only sent to TLS servers...

PT-2026-64471

URI nameConstraints from constrained intermediate CAs are parsed but not enforced during certificate chain verification in wolfcrypt/src/asn.c. A compromised or malicious sub-CA could issue leaf certificates with URI SAN entries that violate the nameConstraints of the issuing CA, and wolfSSL woul...

PT-2026-64458

wolfSSL before 5.4.0 allows remote attackers to cause a denial of service via DTLS because a check for return-routability can be skipped...

PT-2026-64456

In wolfSSL before 5.2.0, certificate validation may be bypassed during attempted authentication by a TLS 1.3 client to a TLS 1.3 server. This occurs when the sig algo field differs between the certificate verify message and the certificate message...