Heap-based Buffer Overflow

Overview Affected versions of this package are vulnerable to Heap-based Buffer Overflow in the fullpacket function during Encrypt-then-MAC cipher negotiation. An attacker can corrupt heap metadata and potentially achieve arbitrary code execution or cause a denial of service by sending a specially...

EUVD-2026-48733

In epa4all, prior to version 2026-05-20, an attacker who can intercept the TLS connection between epa4all and the ePA backend can complete the VAU handshake with attacker-controlled keys and obtain the session encryption keys. All inner HTTP traffic patient consent decisions, medication data,...

CVE-2026-48021 epa4all Security Incident: Implement keystore based on Telematik TSL, implement hostname check and certificate check for lib-vau

In epa4all, prior to version 2026-05-20, an attacker who can intercept the TLS connection between epa4all and the ePA backend can complete the VAU handshake with attacker-controlled keys and obtain the session encryption keys. All inner HTTP traffic patient consent decisions, medication data,...

CVE-2026-48021 epa4all Security Incident: Implement keystore based on Telematik TSL, implement hostname check and certificate check for lib-vau

In epa4all, prior to version 2026-05-20, an attacker who can intercept the TLS connection between epa4all and the ePA backend can complete the VAU handshake with attacker-controlled keys and obtain the session encryption keys. All inner HTTP traffic patient consent decisions, medication data,...

DEBIAN-CVE-2026-66035

libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packetlength smaller than the cipher's block size during Encrypt-then-M...

CVE-2026-66033

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2ciphercrypt function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit...

DEBIAN-CVE-2026-66033

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2ciphercrypt function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit...

CVE-2026-66035

libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packetlength smaller than the cipher's block size during Encrypt-then-M...

UBUNTU-CVE-2026-66035

libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packetlength smaller than the cipher's block size during Encrypt-then-M...

CVE-2026-66033

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2ciphercrypt function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit...

UBUNTU-CVE-2026-66033

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2ciphercrypt function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit...

CVE-2026-66035 libssh2 Heap Buffer Overflow via ETM Cipher Negotiation

libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packetlength smaller than the cipher's block size during Encrypt-then-M...

EUVD-2026-48722

libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packetlength smaller than the cipher's block size during Encrypt-then-M...

CVE-2026-66035

CVE-2026-66035 affects libssh2 up to 1.11.1 and was fixed in commit 42e33d8. The vulnerability is a pre-authentication heap buffer overflow in the Encrypt-then-MAC (ETM) cipher negotiation path. In libssh2’s fullpacket() implemented under src/transport.c, the ETM code path allocates a buffer of p...

CVE-2026-66035

libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packetlength smaller than the cipher's block size during Encrypt-then-M...

CVE-2026-66035 libssh2 Heap Buffer Overflow via ETM Cipher Negotiation

libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packetlength smaller than the cipher's block size during Encrypt-then-M...

CVE-2026-66035 libssh2 Heap Buffer Overflow via ETM Cipher Negotiation

libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packetlength smaller than the cipher's block size during Encrypt-then-M...

CVE-2026-66033

CVE-2026-66033 affects libssh2 up to 1.11.1. A pre-authentication integer underflow in the ssh2_cipher_crypt() function (src/openssl.c) allows a malicious SSH server to crash a connecting client during handshake by negotiating AES-GCM ciphers. The underflow (blocksize − aadlen − taglen) can trigg...

CVE-2026-66033

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2ciphercrypt function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit...

CVE-2026-66033 libssh2 Integer Underflow DoS via AES-GCM Cipher Negotiation

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2ciphercrypt function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit...