How to Fix CVE-2026-34514: aiohttp (Bundle Sibling)
*By Sai Kiran Pandrala*
Last verified: 2026-05-25
| Severity | CVSS 2.7, Low |
|---|---|
| Actively exploited? | No |
| Affected | Aio-libs aiohttp (< 3.13.4) |
| Fixed in | Same patched build as CVE-2026-22815 |
| Type (CWE) | CWE-113: CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting') |
CVE-2026-34514 is a sibling vulnerability in the same Aio-libs aiohttp advisory bundle as CVE-2026-22815. The same patched build closes every CVE in the bundle, so the remediation procedure for CVE-2026-34514 matches the primary write-up.
What is different about CVE-2026-34514?
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, an attacker who controls the content_type parameter in aiohttp could use this to inject extra headers or similar exploits. This issue has been patched in version 3.13.4.
Impact is consistent with the bundle: compromise of the affected component as described in the vendor advisory. The patched build closes every code path in the advisory in one update.
How to fix CVE-2026-34514
Apply the patched build per the primary write-up: How to Fix CVE-2026-22815.
For a quick check, confirm the running version of aiohttp:
# Confirm the installed version via your package manager
dpkg -l | grep -i aiohttp # Debian/Ubuntu
rpm -qa | grep -i aiohttp # RHEL/CentOS/Rocky
Frequently asked questions
Is CVE-2026-34514 being actively exploited?
Not at the time of writing. It is not listed in CISA's Known Exploited Vulnerabilities catalog. That status can change, so monitor the vendor advisory and the KEV catalog if the system is exposed.
How severe is CVE-2026-34514?
CVSS rates it 2.7 (Low). Use that score to set your patch priority alongside the other items in your queue.
Do I have to take aiohttp offline to apply the patch?
It depends on the deployment. High-availability or clustered installs can usually patch one node at a time with no full outage. Standalone installs typically need a short restart. Always follow the vendor's documented upgrade steps.
What if my vulnerability scanner still flags CVE-2026-34514 after I patch?
Re-run the scan after a service restart, then confirm the scanner's plugin set is up to date. Some scanners detect by banner version only and lag the official fix metadata by a release.
References
- Official vendor advisory: https://github.com/aio-libs/aiohttp/security/advisories/GHSA-2vrm-gr82-f7m5
- NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2026-34514
- CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
- Primary write-up: How to Fix CVE-2026-22815
*Written by Sai Kiran Pandrala. Last verified 2026-05-25. Part of the Aio-libs aiohttp advisory bundle. Full procedure at how-to-fix-cve-2026-22815.*