CVE-2026-28755
What it is
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_stream_ssl_module module due to the improper handling of revoked certificates when configured with the ssl_verify_client on and ssl_ocsp on directives, allowing the TLS handshake to succeed even after an OCSP check identifies the certificate as revoked. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. Limited direct impact.
- Exploit odds
- 0.1% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.1% in the next 30 days (EPSS).
- Severity: 5.3 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.1% · EPSS, next 30 days
- Weakness
- CWE-863 · Incorrect authorization
- Record status
- Analyzed
Affected
- f5 nginx Plus r33
- f5 nginx Plus r34
- f5 nginx Plus r35
- f5 nginx Plus r36
- f5 nginx Open Source ≤ 0.9.7
- f5 nginx Open Source < 1.28.3
- f5 nginx Open Source < 1.29.7
Attack profile CVSS 4.0 · 5.3
- Attack vector
- Network
- Complexity
- Low
- Attack requirements
- None
- Privileges needed
- Low
- User interaction
- None
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/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
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-28755.md and follow it. Check whether this project is affected by CVE-2026-28755. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
