2.3
LOW CVSS 4.0
CVE-2026-65655
Temporal UI Server may set OAuth credential cookies without Secure behind a TLS-terminating reverse proxy
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.

INFO

Published Date :

Aug. 11, 2026, 8:18 p.m.

Last Modified :

Aug. 11, 2026, 8:18 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-65655 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 LOW 61241ed8-fa44-4f23-92db-b8c443751968
CVSS 4.0 LOW [email protected]
Solution
Ensure secure cookie attributes are correctly set when using OAuth and TLS termination at a reverse proxy.
  • Configure TLS re-encryption between proxy and UI server.
  • Enforce HTTPS-only connections for Temporal UI Server.
  • Update Temporal UI Server to latest version.
  • Review identity provider cookie security settings.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-65655 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-65655 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-65655 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-65655 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 11, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://github.com/temporalio/ui-server', 'vendor': 'Temporal Technologies, Inc.', 'modules': ['OIDC authentication cookies'], 'product': 'Temporal UI Server', 'versions': [{'status': 'affected', 'version': '2.7.0', 'lessThan': '2.53.2', 'versionType': 'semver'}], 'packageName': 'github.com/temporalio/ui-server/v2', 'programFiles': ['server/auth/auth.go', 'server/route/auth.go'], 'collectionURL': 'https://pkg.go.dev', 'defaultStatus': 'unaffected'}]
    Added 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.
    Added CVSS V4.0 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
    Added CWE CWE-614
    Added Reference https://github.com/temporalio/ui-server/blob/v2.53.1/server/auth/auth.go#L87-L153
    Added Reference https://github.com/temporalio/ui-server/blob/v2.53.1/server/route/auth.go#L281-L316
    Added Reference https://github.com/temporalio/ui-server/commit/7b9ff533fb51beba75497c0a192c66775c08f279
    Added Reference https://github.com/temporalio/ui-server/commit/821cf598371353f1b579dfe1e87aeb3638b041d6
    Added Reference https://github.com/temporalio/ui-server/commit/8876b80b63003688ab736f45ef28885695a4f6db
    Added Reference https://github.com/temporalio/ui-server/releases/tag/v2.53.1
    Added Reference https://github.com/temporalio/ui-server/releases/tag/v2.53.2
    Added Reference https://github.com/temporalio/ui/pull/3806
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.