Temporal UI Server may set OAuth credential cookies without Secure behind a TLS-terminating reverse proxy
Summary
| CVE | CVE-2026-65655 |
|---|---|
| State | PUBLISHED |
| Assigner | Temporal |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-11 20:18:31 UTC |
| Updated | 2026-08-11 21:17:45 UTC |
| Description | When OAuth authentication is enabled and browser-facing TLS terminates at a reverse proxy that forwards the callback to Temporal UI Server over HTTP, affected versions derive authentication-cookie Secure attributes from the proxy-to-server connection. Temporal UI Server can therefore issue access-token cookies, and refresh-token cookies when provided by the identity provider, without Secure even though the browser completed login over HTTPS. A victim who visits attacker-controlled content while a credential remains live may expose that credential only if the attacker can also steer traffic for the UI hostname, prevent the browser's HTTPS connection from succeeding, serve the hostname over HTTP, and read a later same-site plaintext request. A malicious website alone cannot read the cookie, and passive observation of a successful TLS connection is insufficient. Effective HSTS, a blocking HTTPS-only warning, or TLS re-encryption between the proxy and Temporal UI Server prevents the demonstrated disclosure path. A recovered credential may be replayed within the victim's assigned permissions. Refresh-token replay additionally depends on the identity provider's issuance, expiry, rotation, and reuse-detection behavior. |
Risk And Classification
Primary CVSS: v4.0 2.3 LOW from [email protected]
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/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
Problem Types: CWE-614 | CWE-614 CWE-614: Sensitive Cookie in HTTPS Session Without 'Secure' Attribute
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 2.3 | LOW | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 2.3 | LOW | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/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
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Temporal Technologies Inc. | Temporal UI Server | affected 2.7.0 2.53.2 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/temporalio/ui-server/releases/tag/v2.53.1 | [email protected] | github.com | |
| github.com/temporalio/ui-server/commit/821cf598371353f1b579dfe1e87aeb363... | [email protected] | github.com | |
| github.com/temporalio/ui-server/commit/8876b80b63003688ab736f45ef2888569... | [email protected] | github.com | |
| github.com/temporalio/ui-server/blob/v2.53.1/server/auth/auth.go | [email protected] | github.com | |
| github.com/temporalio/ui-server/releases/tag/v2.53.2 | [email protected] | github.com | |
| github.com/temporalio/ui-server/blob/v2.53.1/server/route/auth.go | [email protected] | github.com | |
| github.com/temporalio/ui/pull/3806 | [email protected] | github.com | |
| github.com/temporalio/ui-server/commit/7b9ff533fb51beba75497c0a192c66775... | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: An external security researcher who reported this issue responsibly to Temporal Technologies (en)
Additional Advisory Data
Solutions
CNA: Upgrade to Temporal UI Server v2.53.2 or later. The fix derives the authentication-cookie Secure attribute from the configured browser-facing OAuth callback URL instead of the proxy-to-server connection and applies that decision consistently to all authentication cookies.
Workarounds
CNA: Configure TLS between the reverse proxy and Temporal UI Server, enforce HSTS for the public UI hostname, and block plaintext HTTP. These controls prevent the demonstrated disclosure path but do not correct the configuration-dependent cookie attribute.