CVE-2026-12740
Plack::Middleware::OAuth versions through 0.10 for Perl do not support the OAuth 2.0 state parameter
Description
Plack::Middleware::OAuth versions through 0.10 for Perl do not support the OAuth 2.0 state parameter. RequestTokenV2 builds the provider authorization redirect without issuing a state value, and AccessTokenV2 exchanges the callback code and registers the resulting token into the session (register_session) without verifying that the callback corresponds to an authorization request this session initiated. Any application that uses this middleware for OAuth 2.0 login is exposed to login cross-site request forgery: because the callback is not bound to the session that began the flow, an attacker who starts an authorization with their own provider account can deliver the resulting callback to a victim, causing the victim's session to complete the attacker's authorization and associating the attacker's provider identity and access token with that session. Where the application persists this as an account link, the attacker may retain access to the victim's account through their own provider credentials.
INFO
Published Date :
July 4, 2026, 6:16 p.m.
Last Modified :
July 6, 2026, 6:16 p.m.
Remotely Exploit :
Yes !
Source :
9b29abf9-4ab0-4765-b253-1875cd9b441e
Affected Products
The following products are affected by CVE-2026-12740
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 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update Plack::Middleware::OAuth to a non-vulnerable version.
- Ensure state parameter is used in OAuth 2.0 flows.
- Validate callbacks against initiated requests.
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-2026-12740.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-12740 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-2026-12740
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-2026-12740 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-12740 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.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 06, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Added SSVC {'id': 'CVE-2026-12740', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-06T13:54:10.583390Z'} -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Jul. 04, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/07/04/10 -
New CVE Received by 9b29abf9-4ab0-4765-b253-1875cd9b441e
Jul. 04, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/c9s/Plack-Middleware-OAuth', 'vendor': 'CORNELIUS', 'product': 'Plack::Middleware::OAuth', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'custom', 'lessThanOrEqual': '0.10'}], 'packageName': 'Plack-Middleware-OAuth', 'programFiles': ['lib/Plack/Middleware/OAuth/Handler/AccessTokenV2.pm', 'lib/Plack/Middleware/OAuth/Handler/RequestTokenV2.pm'], 'collectionURL': 'https://cpan.org/modules', 'defaultStatus': 'unaffected'}] Added Description Plack::Middleware::OAuth versions through 0.10 for Perl do not support the OAuth 2.0 state parameter. RequestTokenV2 builds the provider authorization redirect without issuing a state value, and AccessTokenV2 exchanges the callback code and registers the resulting token into the session (register_session) without verifying that the callback corresponds to an authorization request this session initiated. Any application that uses this middleware for OAuth 2.0 login is exposed to login cross-site request forgery: because the callback is not bound to the session that began the flow, an attacker who starts an authorization with their own provider account can deliver the resulting callback to a victim, causing the victim's session to complete the attacker's authorization and associating the attacker's provider identity and access token with that session. Where the application persists this as an account link, the attacker may retain access to the victim's account through their own provider credentials. Added CWE CWE-352 Added Reference https://datatracker.ietf.org/doc/html/rfc6749#section-10.12 Added Reference https://github.com/c9s/Plack-Middleware-OAuth/pull/13 Added Reference https://rt.cpan.org/Ticket/Display.html?id=179874 Added Reference https://security.metacpan.org/patches/P/Plack-Middleware-OAuth/0.10/CVE-2026-12740-r1.patch