Affected: OpenSSL, Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

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 to Denial of Service for an application.

The line-buffering BIO filter (BIO_f_linebuffer) is not used by default in TLS/SSL data paths. In OpenSSL command-line applications, it is typically only pushed onto stdout/stderr on VMS systems. Third-party applications that explicitly use this filter with a BIO chain that can short-write and that write large, newline-free data influenced by an attacker would be affected. However, the circumstances where this could happen are unlikely to be under attacker control, and BIO_f_linebuffer is unlikely to be handling non-curated data controlled by an attacker. For that reason the issue was assessed as Low severity.

The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the BIO implementation is outside the OpenSSL FIPS module boundary.

OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0, 1.1.1 and 1.0.2 are vulnerable to this issue.

Affected: Ubuntu:22.04:LTS: openssl, Ubuntu:24.04:LTS: openssl, Ubuntu:25.10: openssl

Stanislav Fort, Petr Šimeček, and Hamza discovered that OpenSSL incorrectly validated PBMAC1 parameters when doing PKCS#12 MAC verification. An attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. This issue only affected Ubuntu 25.10. (CVE-2025-11187)

Stanislav Fort discovered that OpenSSL incorrectly parsed CMS AuthEnvelopedData messages. An attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. (CVE-2025-15467)

Stanislav Fort discovered that OpenSSL incorrectly handled memory in the SSL_CIPHER_find() function. An attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. This issue only affected Ubuntu 25.10. (CVE-2025-15468)

Stanislav Fort discovered that the OpenSSL "openssl dgst" command line tool incorrectly truncated data to 16MB. An attacker could posibly use this issue to hide unauthenticated data beyond the 16MB limit. This issue only affected Ubuntu 25.10. (CVE-2025-15469)

Tomas Dulka and Stanislav Fort discovered that OpenSSL incorrectly handled memory with TLS 1.3 connections using certificate compression. An attacker could possibly use this issue to consume resources, leading to a denial of service. This issue only affected Ubuntu 25.10. (CVE-2025-66199)

Petr Simecek and Stanislav Fort discovered that OpenSSL incorrectly handled memory when writing large data into a BIO chain. An attacker could possibly use this issue to con…