How severe is CVE-2026-40460?

CVE-2026-40460 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability low.

Is CVE-2026-40460 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-40460?

CVE-2026-40460 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-2026-40460?

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

Does CVE-2026-40460 have an EU (EUVD) identifier?

Yes. CVE-2026-40460 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29974.

When was CVE-2026-40460 published?

CVE-2026-40460 was published on 2026-05-13 and last updated on 2026-06-29.

CVE-2026-40460

CVE-2026-40460 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-290.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v4: 6.9
EPSS exploit prediction: 0% (29th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-29974
Weakness: CWE-290
Affected product: F5 Dos
Published: 2026-05-13
Last modified: 2026-06-29

Description

When NGINX Plus or NGINX Open Source are configured to use the HTTP/3 QUIC module, an attacker may be able to spoof their source IP address allowing for bypass of authorization or bypass of rate limiting. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Frequently asked questions

What is CVE-2026-40460?: When NGINX Plus or NGINX Open Source are configured to use the HTTP/3 QUIC module, an attacker may be able to spoof their source IP address allowing for bypass of authorization or bypass of rate limiting. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
How severe is CVE-2026-40460?: CVE-2026-40460 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability low.
Is CVE-2026-40460 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-40460?: CVE-2026-40460 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-2026-40460?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-40460 have an EU (EUVD) identifier?: Yes. CVE-2026-40460 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29974.
When was CVE-2026-40460 published?: CVE-2026-40460 was published on 2026-05-13 and last updated on 2026-06-29.

References

https://my.f5.com/manage/s/article/K000161068

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:*:*

More vulnerabilities in F5 Dos

CVE-2026-42055 — High (CVSS 8.1): NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module and…
CVE-2026-42945 — High (CVSS 8.1): NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists…
CVE-2026-42946 — Medium (CVSS 6.5): A vulnerability exists in the ngx_http_scgi_module and ngx_http_uwsgi_module modules that may result in excessive…
CVE-2026-48142 — Medium (CVSS 4.8): NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module. When content is served or…
CVE-2026-42934 — Medium (CVSS 4.8): NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module. When charset,…
CVE-2026-40701 — Medium (CVSS 4.8): NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_ssl_module module when the…

All CVEs affecting F5 Dos →

Other CWE-290 vulnerabilities

CVE-2026-48567 — Critical (CVSS 10.0): Authentication bypass by spoofing in Azure HorizonDB allows an unauthorized attacker to elevate privileges over a…
CVE-2026-6213 — Critical (CVSS 10.0): A vulnerability in Remote Spark SparkView before build 1122 allows an attacker to bypasses the local connection check…
CVE-2026-39858 — Critical (CVSS 10.0): Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a high…
CVE-2025-66570 — Critical (CVSS 10.0): cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.27.0, a vulnerability…
CVE-2025-34063 — Critical (CVSS 10.0): A cryptographic authentication bypass vulnerability exists in OneLogin AD Connector prior to 6.1.5 due to the exposure…
CVE-2023-22814 — Critical (CVSS 10.0): An authentication bypass issue via spoofing was discovered in the token-based authentication mechanism that could allow…

Browse all CWE-290 vulnerabilities →