Medium 5.9Published Feb 4, 2026

CVE-2026-1642NGINX vulnerability

Updated under an hour ago (Oct 27, 2026, 12:10 AM ET)

Does this affect you?

It affects F5 NGINX Open Source and 4 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for F5 NGINX Open Source

Exploited in the last 30 days

A vulnerability exists in NGINX OSS and NGINX Plus when configured to proxy to upstream Transport Layer Security (TLS) servers. An attacker with a man-in-the-middle (MITM) position on the upstream server side—along with conditions beyond the attacker's control—may be able to inject plain text data into the response from an upstream proxied server. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

CVSS: 5.9 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Weakness (CWE): CWE-349
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: f5
NVD analysis: Analyzed
Record last updated: Feb 5, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

F5 NGINX Open Source f5:nginx_open_source (from the name)	from 1.3.0 before 1.29.5; fixed at 1.28.2	CNA record
F5 NGINX Plus f5:nginx_plus (from the name)	from R36 before R36 P2; from R35 before R35 P1; from R34; from R33; from R32 before R32 P4	CNA record
f5 nginx_gateway_fabric f5:nginx_gateway_fabric	from 1.2.0 through 1.6.2; from 2.0.0 before 2.4.1	NVD
f5 nginx_ingress_controller f5:nginx_ingress_controller	from 3.4.0 through 3.7.2; from 4.0.0 through 4.0.1; from 5.0.0 before 5.3.3	NVD
f5 nginx_instance_manager f5:nginx_instance_manager	from 2.15.1 through 2.21.0	NVD
f5 nginx_open_source f5:nginx_open_source	from 1.3.0 before 1.28.2; from 1.29.0 before 1.29.5	NVD
f5 nginx_plus f5:nginx_plus	from r33 before r35; r32; r32; r32; r32; r33; r33; r33; and 5 more ranges	NVD

References

References

https://my.f5.com/manage/s/article/K000159824	vendor-advisory
http://www.openwall.com/lists/oss-security/2026/02/05/1	mailing-list, third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.