Severity by source
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
Primary rating from Vendor (f5).
CVSS VectorVendor: f5
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Lifecycle Timeline
3DescriptionCVE.org
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_ssl_module module when the ssl_verify_client directive is set to "on" or "optional," and the ssl_ocsp directive is set to "on" or the leaf parameters are configured with a resolver. With this configuration, an unauthenticated attacker can send requests along with conditions beyond its control that may cause a heap-use-after-free error in the NGINX worker process. This vulnerability may result in limited modification of data or the NGINX worker process restarting.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
AnalysisAI
Heap-use-after-free in NGINX Plus and NGINX Open Source allows unauthenticated remote attackers to trigger memory corruption in the worker process when ssl_verify_client is set to 'on' or 'optional' and ssl_ocsp is configured with a resolver. Exploitation can cause limited information disclosure or worker process restart, with CVSS 4.8 reflecting moderate impact constrained by high attack complexity. No public exploit code or active exploitation has been identified at time of analysis.
Technical ContextAI
The vulnerability resides in the ngx_http_ssl_module, which handles TLS/SSL processing in NGINX. When OCSP (Online Certificate Status Protocol) validation is enabled via the ssl_ocsp directive with a resolver configured, and client certificate verification is active (ssl_verify_client 'on' or 'optional'), a use-after-free condition (CWE-416) occurs in heap memory management during request handling. The flaw stems from improper lifecycle management of memory objects after OCSP stapling or client certificate verification operations, allowing an attacker to trigger access to freed memory regions. The attack does not require authentication, as the vulnerability is exposed at the TLS handshake or early request processing stage before application-level authentication.
RemediationAI
Apply the vendor-released patch from F5 for NGINX Plus and NGINX Open Source as documented in advisory K000161021 (https://my.f5.com/manage/s/article/K000161021). Exact patched versions are available in the F5 advisory. Immediate workaround for organizations unable to patch: disable the ssl_ocsp directive (set ssl_ocsp off) or remove resolver configuration from ssl_ocsp parameters, which eliminates the vulnerable code path while preserving client certificate verification if ssl_verify_client remains configured. Alternative workaround: restrict access to the affected NGINX instance via network ACLs or WAF rules to reduce attack surface, though this does not eliminate the vulnerability. Note that disabling OCSP validation may impact compliance requirements for real-time certificate status validation in regulated environments. Upgrade to patched versions as soon as possible after validation in lower environments.
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NGINX worker process crashes via null pointer dereference in the mail authentication module when CRAM-MD5 or APOP authen
When the NGINX Plus is configured to use the MQTT pre-read module, undisclosed requests can cause an increase in memory
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Same weakness CWE-416 – Use After Free
View allSame technique Information Disclosure
View allVendor StatusVendor
SUSE
Severity: Medium| Product | Status |
|---|---|
| SUSE Linux Enterprise High Performance Computing 15 SP7 SUSE Linux Enterprise Module for Server Applications 15 SP7 SUSE Linux Enterprise Server 15 SP7 SUSE Linux Enterprise Server for SAP Applications 15 SP7 | Fixed |
| SUSE Linux Enterprise Server 15 SP6-LTSS | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | Fixed |
| openSUSE Tumbleweed | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | Affected |
| SUSE Linux Enterprise Server 16.0 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | Affected |
| SUSE Manager Proxy LTS 4.3 | Affected |
| SUSE Manager Retail Branch Server LTS 4.3 | Affected |
| SUSE Manager Server LTS 4.3 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | Fixed |
| SUSE Linux Enterprise Module for Server Applications 15 SP7 | Fixed |
| SUSE Linux Enterprise Server 15 SP7 | Fixed |
| SUSE Linux Enterprise Server 16.0 | Fixed |
| SUSE Linux Enterprise Server 16.1 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | Fixed |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | Fixed |
| SUSE Linux Enterprise Module for Server Applications 15 SP4 | Fixed |
| SUSE Linux Enterprise Module for Server Applications 15 SP5 | Fixed |
| SUSE Linux Enterprise Module for Server Applications 15 SP6 | Fixed |
| SUSE Linux Enterprise Server 15 SP4 | Fixed |
| SUSE Linux Enterprise Server 15 SP4-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP5 | Fixed |
| SUSE Linux Enterprise Server 15 SP5-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP6 | Fixed |
| SUSE Linux Enterprise Server 15 SP6-LTSS | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | Fixed |
| SUSE Manager Proxy 4.3 | Fixed |
| SUSE Manager Proxy LTS 4.3 | Fixed |
| SUSE Manager Retail Branch Server 4.3 | Fixed |
| SUSE Manager Retail Branch Server LTS 4.3 | Fixed |
| SUSE Manager Server 4.3 | Fixed |
| SUSE Manager Server LTS 4.3 | Fixed |
| SUSE CaaS Platform 4.0 | Fixed |
| SUSE Enterprise Storage 6 | Fixed |
| SUSE Enterprise Storage 7 | Fixed |
| SUSE Enterprise Storage 7.1 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | Fixed |
| SUSE Linux Enterprise Module for Server Applications 15 SP1 | Fixed |
| SUSE Linux Enterprise Module for Server Applications 15 SP2 | Fixed |
| SUSE Linux Enterprise Module for Server Applications 15 SP3 | Fixed |
| SUSE Linux Enterprise Real Time 15 SP2 | Fixed |
| SUSE Linux Enterprise Real Time 15 SP3 | Fixed |
| SUSE Linux Enterprise Real Time 15 SP4 | Fixed |
| SUSE Linux Enterprise Server 15 SP1 | Fixed |
| SUSE Linux Enterprise Server 15 SP1-BCL | Fixed |
| SUSE Linux Enterprise Server 15 SP1-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP2 | Fixed |
| SUSE Linux Enterprise Server 15 SP2-BCL | Fixed |
| SUSE Linux Enterprise Server 15 SP2-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP3 | Fixed |
| SUSE Linux Enterprise Server 15 SP3-BCL | Fixed |
| SUSE Linux Enterprise Server 15 SP3-LTSS | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | Fixed |
| SUSE Manager Proxy 4.0 | Fixed |
| SUSE Manager Proxy 4.1 | Fixed |
| SUSE Manager Proxy 4.2 | Fixed |
| SUSE Manager Retail Branch Server 4.0 | Fixed |
| SUSE Manager Retail Branch Server 4.1 | Fixed |
| SUSE Manager Retail Branch Server 4.2 | Fixed |
| SUSE Manager Server 4.0 | Fixed |
| SUSE Manager Server 4.1 | Fixed |
| SUSE Manager Server 4.2 | Fixed |
| openSUSE Leap 15.3 | Fixed |
| openSUSE Leap 15.4 | Fixed |
| openSUSE Leap 15.5 | Fixed |
| openSUSE Leap 15.6 | Fixed |
| suse/rmt-nginx | Fixed |
| private-registry/harbor-nginx suse/nginx | Fixed |
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-29981
GHSA-x88q-x2r7-vg3g