CVE-2026-54276 — aiohttp
Fix: aio-libs/aiohttp@38d1606CVE-2026-54276 is a Information Exposure vulnerability in aiohttp. A fix is available for aiohttp — see the affected versions and patch details below.
AIOHTTP: DigestAuthMiddleware Applies Credentials to Cross-Origin Redirect Challenges
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-54276.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
aiohttpReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
DigestAuthMiddleware can send an authentication response after following a cross-origin redirect.
Impact
If the client follows a redirect (the default option) to an attacker controlled domain, the attacker may be able to extract the auth digest.
This likely requires an open redirect vulnerability or similar on the target domain for an attacker to be able to execute. Further, the attacker is only receiving the digest, so should only be able to extract the user's credentials if the cryptography is weak or there is some kind of password reuse.
Workaround
Disable follow_redirects if this is a concern.
Patch: https://github.com/aio-libs/aiohttp/commit/38d16060037e1bfcd6d677abababa3c2a4bb58fa
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | aiohttp | all versions | 3.14.1pip install --upgrade 'aiohttp==3.14.1' |
Affected Products
aiohttpaiohttpDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for aiohttp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update aiohttp to 3.14.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-54276 is resolved across your whole dependency graph.
Workarounds
Stop reflecting attacker-controlled destinations: resolve every redirect target against an allowlist of paths or hosts you own, prefer a server-side key over a full URL in the request, and reject absolute URLs entirely where the flow only ever needs a relative one.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This Low impact information disclosure flaw in aiohttp's DigestAuthMiddleware allows an authentication response to be sent after a cross-origin redirect. Exploitation requires an existing open redirect vulnerability on the target domain and relies on weak cryptography or password reuse to extract user credentials from…
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.Source: Red Hat security advisory for CVE-2026-54276 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2026-54276 in your dependencies?
Find it across PyPI, including transitive dependencies.