Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/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
Remote unauthenticated request triggers the flaw (AV:N/PR:N/UI:N); limited memory read gives C:L, no integrity impact, and repeated worker restarts justify A:H; config prerequisite reduces population, not attacker complexity.
AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
Primary rating from Vendor (f5).
CVSS VectorVendor: f5
Lifecycle Timeline
5DescriptionCVE.org
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_slice_module module. When the slice directive and unnamed regex captures are configured or when a background cache update happens, unauthenticated attackers can send requests that may cause uninitialized memory access in the NGINX worker process, leading to limited disclosure of memory or a restart.
Impact: This vulnerability may allow remote, unauthenticated attackers to have limited control to disclose memory contents or restart the NGINX worker process. There is no control plane exposure; this is a data plane issue only. Note: The ngx_http_slice_module module is not enabled by default; it's enabled with the --with-http_slice_module configuration parameter.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Articles & Coverage 1
AnalysisAI
Limited memory disclosure and worker-process restart in NGINX Plus and NGINX Open Source arise when the optional ngx_http_slice_module is compiled in and configured alongside unnamed regex captures, or when a background cache update occurs, letting remote attackers trigger uninitialized memory access (CWE-908) in the data plane. The CVSS:4.0 vector (AV:N/AC:L/PR:N/UI:N) indicates unauthenticated network exploitation with no user interaction, scored 8.8. There is no public exploit identified at time of analysis and no CISA KEV listing; F5 has released a patch and the issue does not affect the control plane.
Technical ContextAI
The flaw resides in ngx_http_slice_module, an add-on module that splits responses into byte-range 'slices' to make large files more cacheable (commonly paired with proxy_cache for efficient partial-content and range handling). It is not built into stock binaries and must be enabled at compile time via --with-http_slice_module. CWE-908 (Use of Uninitialized Resource) is the root-cause class: under specific request-processing paths - the slice directive combined with unnamed regex captures in location/rewrite configuration, or during a background cache update (proxy_cache_background_update) - the worker reads memory that was never initialized. The affected code paths are confirmed against F5 NGINX Plus (cpe:2.3:a:f5:nginx_plus) and NGINX Open Source (cpe:2.3:a:f5:nginx_open_source); exact version ranges are not enumerated in the provided data, and versions past End of Technical Support were not evaluated.
RemediationAI
Patch available per vendor advisory: upgrade to the fixed NGINX Plus / NGINX Open Source release identified in F5 article K000162100 (https://my.f5.com/manage/s/article/K000162100); exact fixed version numbers are not included in the provided data and must be taken from that advisory. As a compensating control until patching, determine whether your binary was built with the slice module (nginx -V | grep http_slice_module) - if it is not present, you are not exposed. Where the module is compiled in but not required, rebuild without --with-http_slice_module; where it is needed, remove the risky configuration pattern by eliminating unnamed regex captures in locations/rewrites that coexist with the slice directive (switch to named captures), and consider disabling proxy_cache_background_update to close the background-cache-update trigger, accepting the trade-off of stale-while-revalidate behavior being lost and clients occasionally waiting on cache refreshes. These are data-plane-only changes; no control-plane action is required.
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Same weakness CWE-908 – Use of Uninitialized Resource
View allSame technique Information Disclosure
View allVendor StatusVendor
SUSE
Severity: Important| Product | Status |
|---|---|
| openSUSE Tumbleweed | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP7 | Affected |
| SUSE Linux Enterprise Server 15 SP7 | Affected |
| SUSE Linux Enterprise Server 16.1 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP4 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP5 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP6 | Affected |
| SUSE Linux Enterprise Server 15 SP4 | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP5 | Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP6 | Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | Affected |
| SUSE Manager Proxy 4.3 | Affected |
| SUSE Manager Proxy LTS 4.3 | Affected |
| SUSE Manager Retail Branch Server 4.3 | Affected |
| SUSE Manager Retail Branch Server LTS 4.3 | Affected |
| SUSE Manager Server 4.3 | Affected |
| SUSE Manager Server LTS 4.3 | Affected |
| SUSE CaaS Platform 4.0 | Affected |
| SUSE Enterprise Storage 6 | Affected |
| SUSE Enterprise Storage 7 | Affected |
| SUSE Enterprise Storage 7.1 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP1 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP2 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP3 | Affected |
| SUSE Linux Enterprise Real Time 15 SP2 | Affected |
| SUSE Linux Enterprise Real Time 15 SP3 | Affected |
| SUSE Linux Enterprise Real Time 15 SP4 | Affected |
| SUSE Linux Enterprise Server 15 SP1 | Affected |
| SUSE Linux Enterprise Server 15 SP1-BCL | Affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP2 | Affected |
| SUSE Linux Enterprise Server 15 SP2-BCL | Affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP3 | Affected |
| SUSE Linux Enterprise Server 15 SP3-BCL | Affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | Affected |
| SUSE Manager Proxy 4.0 | Affected |
| SUSE Manager Proxy 4.1 | Affected |
| SUSE Manager Proxy 4.2 | Affected |
| SUSE Manager Retail Branch Server 4.0 | Affected |
| SUSE Manager Retail Branch Server 4.1 | Affected |
| SUSE Manager Retail Branch Server 4.2 | Affected |
| SUSE Manager Server 4.0 | Affected |
| SUSE Manager Server 4.1 | Affected |
| SUSE Manager Server 4.2 | Affected |
| openSUSE Leap 15.3 | Affected |
| openSUSE Leap 15.4 | Affected |
| openSUSE Leap 15.5 | Affected |
| openSUSE Leap 15.6 | Affected |
| private-registry/1.2/harbor-portal private-registry/harbor-nginx private-registry/harbor-portal suse/nginx suse/nginx:1.21 suse/rmt-nginx | Affected |
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-44697
GHSA-vxcv-h5wj-jxr5