CVE-2026-121821
Armeria CORS Policy Security Bypass
Description
A vulnerability has been identified in armeria versions 0.84.0 through 1.42.0, where any-origin CORS policies do not enforce configured path restrictions, allowing an attacker-controlled website visited by an authenticated victim to read sensitive responses from excluded paths when credentials are enabled and the victim's browser sends authentication credentials.
INFO
Published Date :
Nov. 6, 2026, 8:17 a.m.
Last Modified :
Nov. 6, 2026, 8:17 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-121821
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
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update Armeria to version 1.43.0 or later.
- Review and correctly configure CORS path restrictions.
- Avoid sending sensitive data with CORS requests.
- Disable credentials if not strictly necessary.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-121821.
| URL | Resource |
|---|---|
| https://github.com/line/armeria/security/advisories/GHSA-386q-mrg6-jfj8 | |
| https://line.github.io/security-advisory-blog/CVE-2026-121821/ |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-121821 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-2026-121821
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-2026-121821 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-121821 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]
Nov. 06, 2026
Action Type Old Value New Value Added Description A vulnerability has been identified in armeria versions 0.84.0 through 1.42.0, where any-origin CORS policies do not enforce configured path restrictions, allowing an attacker-controlled website visited by an authenticated victim to read sensitive responses from excluded paths when credentials are enabled and the victim's browser sends authentication credentials. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/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 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/121xxx/CVE-2026-121821.json">CVE-2026-121821</a> Added Reference https://github.com/line/armeria/security/advisories/GHSA-386q-mrg6-jfj8 Added Reference https://line.github.io/security-advisory-blog/CVE-2026-121821/