How severe is CVE-2026-42946?

CVE-2026-42946 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability low.

Is CVE-2026-42946 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-42946?

CVE-2026-42946 primarily affects F5 Dos. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-42946?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-42946 have an EU (EUVD) identifier?

Yes. CVE-2026-42946 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30011.

When was CVE-2026-42946 published?

CVE-2026-42946 was published on 2026-05-13 and last updated on 2026-06-18.

CVE-2026-42946

CVE-2026-42946 is a medium-severity vulnerability in F5 Dos with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-789.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v4: 8.3
EPSS exploit prediction: 1% (56th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-30011
Weakness: CWE-789
Affected product: F5 Dos
Published: 2026-05-13
Last modified: 2026-06-18

Description

A vulnerability exists in the ngx_http_scgi_module and ngx_http_uwsgi_module modules that may result in excessive memory allocation or an over-read of data. When scgi_pass or uwsgi_pass is configured, an unauthenticated attacker with man-in-the-middle (MITM) ability to control responses from an upstream server may be able to read the memory of the NGINX worker process or restart it. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Frequently asked questions

What is CVE-2026-42946?: A vulnerability exists in the ngx_http_scgi_module and ngx_http_uwsgi_module modules that may result in excessive memory allocation or an over-read of data. When scgi_pass or uwsgi_pass is configured, an unauthenticated attacker with man-in-the-middle (MITM) ability to control responses from an upstream server may be able to read the memory of the NGINX worker process or restart it. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
How severe is CVE-2026-42946?: CVE-2026-42946 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability low.
Is CVE-2026-42946 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-42946?: CVE-2026-42946 primarily affects F5 Dos. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-42946?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-42946 have an EU (EUVD) identifier?: Yes. CVE-2026-42946 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30011.
When was CVE-2026-42946 published?: CVE-2026-42946 was published on 2026-05-13 and last updated on 2026-06-18.

References

https://my.f5.com/manage/s/article/K000161027

Affected products (8)

cpe:2.3:a:f5:dos:*:*:*:*:*:nginx:*:*
cpe:2.3:a:f5:dos:4.8.0:*:*:*:*:nginx:*:*
cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:nginx_instance_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:*

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