CVE-2026-104939: f5 nginx ingress controller
Vulnerability summary
CVE-2026-104939 is a high (CVSS 8.7) vulnerability in f5 nginx ingress controller. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 28.1% of scored vulnerabilities.
Timeline
- 14-10-2026PublishedVulnerability first disclosed.
- 15-10-2026Last modifiedVulnerability information updated.
Description
Description NGINX Ingress Controller has a vulnerability when implementing an externalAuth policy for ingress. NGINX Ingress Controller may mishandle the HTTP response from an OAuth IdP and allow an attacker to acquire unauthenticated access to protected paths before the proper external authentication can happen. Impact This vulnerability may allow remote attackers unauthenticated access to protected paths. There is no control plane exposure; this is a data plane issue only. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
CVSS metrics
4 scores · 2 sources · 2 versions- NVDNIST8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/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
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
0.36%
Chance of exploitation in the next 30 days
Percentile
28%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
F51 product
- nginx ingress controller≥ 5.6.0, < 5.7.0
1 vendor · 1 product
References
1 links- my.f5.com/manage/s/article/K000162617Vendor Advisory