OpenSSL up to 3.6.0 AuthEnvelopedData Message out-of-bounds write

Summaryinfo

A vulnerability classified as critical was found in OpenSSL up to 3.0.18/3.3.5/3.4.3/3.5.4/3.6.0. This issue affects some unknown processing of the component AuthEnvelopedData Message Handler. Such manipulation leads to out-of-bounds write. This vulnerability is listed as CVE-2025-15467. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, has been found in OpenSSL up to 3.0.18/3.3.5/3.4.3/3.5.4/3.6.0. Affected by this issue is an unknown function of the component AuthEnvelopedData Message Handler. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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 (Auth)EnvelopedData structures that use AEAD ciphers such as AES-GCM, the IV (Initialization Vector) encoded in the ASN.1 parameters is copied into a fixed-size stack buffer without verifying that its length fits the destination. An attacker can supply a crafted CMS message with an oversized IV, causing a stack-based out-of-bounds write before any authentication or tag verification occurs. Applications and services that parse untrusted CMS or PKCS#7 content using AEAD ciphers (e.g., S/MIME (Auth)EnvelopedData with AES-GCM) are vulnerable. Because the overflow occurs prior to authentication, no valid key material is required to trigger it. While exploitability to remote code execution depends on platform and toolchain mitigations, the stack-based write primitive represents a severe risk. The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the CMS implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4, 3.3 and 3.0 are vulnerable to this issue. OpenSSL 1.1.1 and 1.0.2 are not affected by this issue.

The advisory is shared for download at openssl-library.org. This vulnerability is handled as CVE-2025-15467 since 01/06/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 03/19/2026).

The vulnerability scanner Nessus provides a plugin with the ID 296783 (Linux Distros Unpatched Vulnerability : CVE-2025-15467), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.0.19, 3.3.6, 3.4.4, 3.5.5 or 3.6.1 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (296783), EUVD (EUVD-2025-206379) and CERT Bund (WID-SEC-2026-0234). Once again VulDB remains the best source for vulnerability data.

Affected

• IBM VIOS
• IBM AIX
• Debian Linux
• Google Cloud Platform
• Amazon Linux 2
• Red Hat Enterprise Linux
• NetApp Data ONTAP
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• IGEL OS
• SUSE openSUSE
• Fabasoft Cloud
• RESF Rocky Linux
• IBM App Connect Enterprise
• Open Source OpenSSL
• Broadcom Brocade SANnav
• Fortinet FortiPortal
• Meinberg LANTIME
• Red Hat OpenShift
• IBM MQ
• Open Source Camunda
• ABB AC-500

Productinfo

Type

• Network Encryption Software

Name

• OpenSSL

Version

• 3.0
• 3.0.0
• 3.0.1
• 3.0.2
• 3.0.3
• 3.0.4
• 3.0.5
• 3.0.6
• 3.0.7
• 3.0.8
• 3.0.9
• 3.0.10
• 3.0.11
• 3.0.12
• 3.0.13
• 3.0.14
• 3.0.15
• 3.0.16
• 3.0.17
• 3.0.18
• 3.1
• 3.2
• 3.3
• 3.3.0
• 3.3.1
• 3.3.2
• 3.3.3
• 3.3.4
• 3.3.5
• 3.4
• 3.4.0
• 3.4.1
• 3.4.2
• 3.4.3
• 3.5
• 3.5.0
• 3.5.1
• 3.5.2
• 3.5.3
• 3.5.4
• 3.6.0

License

• open-source

Website

• Product: https://www.openssl.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Once again VulDB remains the best source for vulnerability data.

Discussion