CVE-2026-19565
Apache::AppSamurai::Util versions through 1.01 for Perl generate predictable session authentication keys from the clock and process id in CreateSessionAuthKey
Description
Apache::AppSamurai::Util versions through 1.01 for Perl generate predictable session authentication keys from the clock and process id in CreateSessionAuthKey. CreateSessionAuthKey runs five rounds of SHA-256, each over a fresh Time::HiRes reading formatted to six decimal places, the running digest, and the process id. CreateSession calls it with an empty key source on every login, and the optional Keysource directive is the only route to the other branch. The result is 64 hex characters. The microsecond field of the first reading takes one of a million values, the later readings follow it within microseconds, and the process id is drawn from a small range. The key is returned to the browser as the session cookie, and is combined with the configured server key to compute the session id and to encrypt the stored session data. An attacker who knows the second in which a session was created and the process id of the worker that created it can enumerate candidate keys and recover the victim's cookie, bypassing authentication for the protected resources. Each candidate has to be tried against the server, which validates the cookie with a key the attacker does not hold.
INFO
Published Date :
Aug. 23, 2026, 8:16 p.m.
Last Modified :
Oct. 14, 2026, 1:10 p.m.
Remotely Exploit :
Yes !
Source :
9b29abf9-4ab0-4765-b253-1875cd9b441e
Affected Products
The following products are affected by CVE-2026-19565
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 | LOW | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update Apache::AppSamurai::Util to a non-vulnerable version.
- Review and enhance session key generation logic.
- Implement stronger session entropy sources.
- Consider using a cryptographically secure random number generator.
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-2026-19565.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-19565 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-2026-19565
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-2026-19565 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-19565 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.
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CVE Translated by [email protected]
Oct. 14, 2026
Action Type Old Value New Value Added Translation Title: Apache::AppSamurai::Util versions through 1.01 for Perl generate predictable session authentication keys from the clock and process id in CreateSessionAuthKey, Description: Las versiones de Apache::AppSamurai::Util hasta la 1.01 para Perl generan claves de autenticación de sesión predecibles a partir del reloj y el ID de proceso en CreateSessionAuthKey. CreateSessionAuthKey ejecuta cinco rondas de SHA-256, cada una sobre una lectura nueva de Time::HiRes formateada a seis decimales, el resumen en ejecución y el ID de proceso. CreateSession lo llama con una fuente de clave vacía en cada inicio de sesión, y la directiva opcional Keysource es la única ruta a la otra rama. El resultado son 64 caracteres hexadecimales. El campo de microsegundos de la primera lectura toma uno de un millón de valores, las lecturas posteriores lo siguen en microsegundos, y el ID de proceso se extrae de un rango pequeño. La clave se devuelve al navegador como la cookie de sesión, y se combina con la clave de servidor configurada para calcular el ID de sesión y para cifrar los datos de sesión almacenados. Un atacante que conoce el segundo en que se creó una sesión y el ID de proceso del trabajador que la creó puede enumerar claves candidatas y recuperar la cookie de la víctima, eludiendo la autenticación para los recursos protegidos. Cada candidato debe ser probado contra el servidor, que valida la cookie con una clave que el atacante no posee. -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 25, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N Added SSVC {'id': 'CVE-2026-19565', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-25T19:31:22.304070Z'} -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Aug. 23, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/08/23/4 -
New CVE Received by 9b29abf9-4ab0-4765-b253-1875cd9b441e
Aug. 23, 2026
Action Type Old Value New Value Added Affected [{'modules': ['Apache::AppSamurai::Util'], 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'custom', 'lessThanOrEqual': '1.01'}], 'packageURL': 'pkg:cpan/Apache-AppSamurai', 'packageName': 'Apache-AppSamurai', 'programFiles': ['lib/Apache/AppSamurai/Util.pm', 'lib/Apache/AppSamurai.pm'], 'collectionURL': 'https://cpan.org/modules', 'defaultStatus': 'unaffected', 'programRoutines': [{'name': 'Apache::AppSamurai::Util::CreateSessionAuthKey'}, {'name': 'Apache::AppSamurai::CreateSession'}]}] Added Description Apache::AppSamurai::Util versions through 1.01 for Perl generate predictable session authentication keys from the clock and process id in CreateSessionAuthKey. CreateSessionAuthKey runs five rounds of SHA-256, each over a fresh Time::HiRes reading formatted to six decimal places, the running digest, and the process id. CreateSession calls it with an empty key source on every login, and the optional Keysource directive is the only route to the other branch. The result is 64 hex characters. The microsecond field of the first reading takes one of a million values, the later readings follow it within microseconds, and the process id is drawn from a small range. The key is returned to the browser as the session cookie, and is combined with the configured server key to compute the session id and to encrypt the stored session data. An attacker who knows the second in which a session was created and the process id of the worker that created it can enumerate candidate keys and recover the victim's cookie, bypassing authentication for the protected resources. Each candidate has to be tried against the server, which validates the cookie with a key the attacker does not hold. Added CWE CWE-341 Added Reference https://metacpan.org/release/PAULDOOM/Apache-AppSamurai-1.01/source/lib/Apache/AppSamurai.pm#L1446-1533 Added Reference https://metacpan.org/release/PAULDOOM/Apache-AppSamurai-1.01/source/lib/Apache/AppSamurai/Util.pm#L106-135