CVE catalog
CVE-2026-34525
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This issue has been patched in version 3.13.4.
- Severity
- Medium · CVSS 6.3
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.29% · Oct 25, 2026
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This issue has been patched in version 3.13.4.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | python-aiohttp | sid | 3.14.3-1 | fixed |
| Debian | python-aiohttp | forky | 3.14.3-1 | fixed |
| Debian | python-aiohttp | trixie | 3.11.16-1+deb13u1 | vulnerable |
| Debian | python-aiohttp | trixie-security | 3.11.16-1+deb13u1 | vulnerable |
| Debian | python-aiohttp | bookworm | 3.8.4-1+deb12u1 | vulnerable |
| Debian | python-aiohttp | bookworm-security | 3.8.4-1+deb12u1 | vulnerable |
| Cpe | python-aiohttp | Not reported | Not reported | vulnerable |
| Cpe | aiohttp | Not reported | 3.13.4 | fixed |
| PyPI | aiohttp | Not reported | 3.13.4 | fixed |
| Cpe | aiohttp | Not reported | 3.13.4 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | python-aiohttp | source | sid | 3.13.5-1 | not yet assigned | Not reported | [1132582] |
| Debian | python-aiohttp | source | forky | 3.13.5-1 | not yet assigned | Not reported | [1132582] |
| Debian | python-aiohttp | source | trixie | (unfixed) | not yet assigned | Not reported | [1132582] |
| Debian | python-aiohttp | source | bookworm | (unfixed) | not yet assigned | Not reported | [1132582] |
| Cpe | aiohttp | cpe | Not reported | 3.13.4 | Not reported | Not reported | Not reported |
| PyPI | aiohttp | PyPI | Not reported | 3.13.4 | Not reported | GHSA-C427-H43C-VF67 | Not reported |
| Cpe | aiohttp | cpe | Not reported | 3.13.4 | Not reported | NVD-CVE-2026-34525 | Not reported |
Notes
[trixie] python-aiohttp: Minor issue [bookworm] python-aiohttp: Minor issue
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [python3-aiohttp]Affected
Source package: [python-aiohttp]
Details (4)
3.8.4-1+deb12u1· amd64 · bookwormAffected
nvd · python-aiohttp · debian · bookworm; nvd · python-aiohttp · debian · 12
3.8.4-1+deb12u1· arm64 · bookwormAffected
nvd · python-aiohttp · debian · bookworm; nvd · python-aiohttp · debian · 12
3.8.4-1+deb12u1· amd64 · bookworm-securityAffected
nvd · python-aiohttp · debian · bookworm; nvd · python-aiohttp · debian · 12
3.8.4-1+deb12u1· arm64 · bookworm-securityAffected
nvd · python-aiohttp · debian · bookworm; nvd · python-aiohttp · debian · 12
- [python-aiohttp-doc]Affected
Source package: [python-aiohttp]
Details (4)
3.8.4-1+deb12u1· all · bookwormAffected
nvd · python-aiohttp · debian · bookworm; nvd · python-aiohttp · debian · 12
3.8.4-1+deb12u1· all · bookwormAffected
nvd · python-aiohttp · debian · bookworm; nvd · python-aiohttp · debian · 12
3.8.4-1+deb12u1· all · bookworm-securityAffected
nvd · python-aiohttp · debian · bookworm; nvd · python-aiohttp · debian · 12
3.8.4-1+deb12u1· all · bookworm-securityAffected
nvd · python-aiohttp · debian · bookworm; nvd · python-aiohttp · debian · 12
[Debian 13 (Trixie)]
- [python3-aiohttp]Affected
Source package: [python-aiohttp]
Details (4)
3.11.16-1+deb13u1· amd64 · trixieAffected
nvd · python-aiohttp · debian · 13
3.11.16-1+deb13u1· arm64 · trixieAffected
nvd · python-aiohttp · debian · 13
3.11.16-1+deb13u1· amd64 · trixie-securityAffected
nvd · python-aiohttp · debian · 13
3.11.16-1+deb13u1· arm64 · trixie-securityAffected
nvd · python-aiohttp · debian · 13
- [python-aiohttp-doc]Affected
Source package: [python-aiohttp]
Details (4)
3.11.16-1+deb13u1· all · trixieAffected
nvd · python-aiohttp · debian · 13
3.11.16-1+deb13u1· all · trixieAffected
nvd · python-aiohttp · debian · 13
3.11.16-1+deb13u1· all · trixie-securityAffected
nvd · python-aiohttp · debian · 13
3.11.16-1+deb13u1· all · trixie-securityAffected
nvd · python-aiohttp · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/suse-su-2026_3059-1.json]
- [https://github.com/aio-libs/aiohttp/commit/53e2e6fc58b89c6185be7820bd2c9f40216b3000]
- [https://github.com/aio-libs/aiohttp/commit/e00ca3cca92c465c7913c4beb763a72da9ed8349]
- [https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4]
- [https://github.com/aio-libs/aiohttp/security/advisories/GHSA-c427-h43c-vf67]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-34525]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-34525]
- [https://osv.dev/vulnerability/GHSA-c427-h43c-vf67]
- [https://security-tracker.debian.org/tracker/CVE-2026-34525]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34525.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2933.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]