OpenSSL up to 3.5.4/3.6.0 dgst signature verification

Summaryinfo

A vulnerability marked as problematic has been reported in OpenSSL up to 3.5.4/3.6.0. Affected by this issue is some unknown functionality of the component dgst. The manipulation leads to signature verification. This vulnerability is referenced as CVE-2025-15469. The attack can only be performed from a local environment. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in OpenSSL up to 3.5.4/3.6.0. It has been rated as problematic. This issue affects an unknown code of the component dgst. The manipulation with an unknown input leads to a signature verification vulnerability. Using CWE to declare the problem leads to CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. Impacted is confidentiality. The summary by CVE is:

Issue summary: The 'openssl dgst' command-line tool silently truncates input data to 16MB when using one-shot signing algorithms and reports success instead of an error. Impact summary: A user signing or verifying files larger than 16MB with one-shot algorithms (such as Ed25519, Ed448, or ML-DSA) may believe the entire file is authenticated while trailing data beyond 16MB remains unauthenticated. When the 'openssl dgst' command is used with algorithms that only support one-shot signing (Ed25519, Ed448, ML-DSA-44, ML-DSA-65, ML-DSA-87), the input is buffered with a 16MB limit. If the input exceeds this limit, the tool silently truncates to the first 16MB and continues without signaling an error, contrary to what the documentation states. This creates an integrity gap where trailing bytes can be modified without detection if both signing and verification are performed using the same affected codepath. The issue affects only the command-line tool behavior. Verifiers that process the full message using library APIs will reject the signature, so the risk primarily affects workflows that both sign and verify with the affected 'openssl dgst' command. Streaming digest algorithms for 'openssl dgst' and library users are unaffected. The FIPS modules in 3.5 and 3.6 are not affected by this issue, as the command-line tools are outside the OpenSSL FIPS module boundary. OpenSSL 3.5 and 3.6 are vulnerable to this issue. OpenSSL 3.4, 3.3, 3.0, 1.1.1 and 1.0.2 are not affected by this issue.

The advisory is shared at openssl-library.org. The identification of this vulnerability is CVE-2025-15469 since 01/06/2026. The exploitation is known to be difficult. An attack has to be approached locally. Neither technical details nor an exploit are publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 296778 (Linux Distros Unpatched Vulnerability : CVE-2025-15469), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.5.5 or 3.6.1 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (296778) and CERT Bund (WID-SEC-2026-0234). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• IBM VIOS
• IBM AIX
• Debian Linux
• Google Cloud Platform
• IBM DataPower Gateway
• Amazon Linux 2
• Red Hat Enterprise Linux
• NetApp Data ONTAP
• Siemens SIMATIC WinCC
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• IGEL OS
• IBM QRadar SIEM
• SUSE openSUSE
• Fabasoft Cloud
• RESF Rocky Linux
• IBM App Connect Enterprise
• Dell BIOS
• Dell PowerScale OneFS
• Siemens SIMATIC STEP 7
• Open Source OpenSSL
• Broadcom Brocade SANnav
• Fortinet FortiPortal
• Meinberg LANTIME
• Red Hat OpenShift
• IBM MQ
• Open Source Camunda
• ABB AC-500
• Dell Secure Connect Gateway
• IBM InfoSphere Information Server
• Splunk Splunk Enterprise
• Phoenix Contact FL MGUARD
• Phoenix Contact FL SWITCH
• Phoenix Contact TC ROUTER
• Dell integrated Dell Remote Access Controller
• Siemens SIMATIC S7
• Insyde UEFI Firmware
• NCP Secure Enterprise VPN Server

Productinfo

Type

• Network Encryption Software

Name

• OpenSSL

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 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/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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