Staging Environment: Content and features may be unstable or change without notice.
Advisory details: vulnrichment / CVE-2026-40594
Advisory ID vulnrichment/CVE-2026-40594
Aliases
Summary pyLoad is a free and open-source download manager written in Python. Prior to 0.5.0b3.dev98, the set_session_cookie_secure before_request handler in src/pyload/webui/app/__init__.py reads the X-Forwarded-Proto header from any HTTP request without validating that the request originates from a trusted proxy, then mutates the global Flask configuration SESSION_COOKIE_SECURE on every request. Because pyLoad uses the multi-threaded Cheroot WSGI server (request_queue_size=512), this creates a race condition where an attacker's request can influence the Secure flag on other users' session cookies — either downgrading cookie security behind a TLS proxy or causing a session denial-of-service on plain HTTP deployments. This vulnerability is fixed in 0.5.0b3.dev98.
Status Published
Exploitability 0.5
Weighted Severity 0.0
Risk
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (1)
CWE-346 Origin Validation Error
System Score Found at
cvssv3.1 4.8
ssvc Track
Reference id Reference type URL
GHSA-mp82-fmj6-f22v Other https://github.com/pyload/pyload/security/advisories/GHSA-mp82-fmj6-f22v
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L Found at None
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: SSVCv2/E:P/A:N/T:P/P:M/B:A/M:M/D:T/2026-04-21T18:01:27Z/ Found at None

Vector: SSVCv2/E:P/A:N/T:P/P:M/B:A/M:M/D:T/2026-04-21T18:01:27Z/

Decision: Track

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/40xxx/CVE-2026-40594.json

Source Advisory: vulnrichment/CVE-2026-40594

View SSVC decision tree 
[{'Exploitation': 'poc'},
 {'Automatable': 'no'},
 {'Technical Impact': 'partial'},
 {'Mission Prevalence': 'minimal'},
 {'Public Well-being Impact': 'material'},
 {'Mission & Well-being': 'medium'}]