Vulnerability in aiohttp (CVE-2026-54275)
Summary
Vulnerability in aiohttp (CVE-2026-54275). Risk of unauthorized operations or information disclosure. Exploitable via server_hostname. Mitigation: upgrade to 3.14.1 or later.
Original description
The description as published by the source.
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, the server_hostname TLS SNI check can be bypassed when an existing connection is reused. If an application makes multiple requests to the same domain, but with different per-request server_hostname parameters, then the later calls may succeed by reusing the existing connection when they should have been rejected due to the TLS SNI check. This vulnerability is fixed in 3.14.1.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-54275 has been found in aiohttp.
Attackers can target a specific entry point like server_hostname over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade aiohttp to 3.14.1 or later.
If unsure, ask your IT team or search "aiohttp CVE-2026-54275" on the vendor's site.
CVE-2026-54275 (aiohttp) — CWE-297 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: server_hostname
Patched: 3.14.1 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-297) exists in aiohttp. Attackers reach the vulnerable code path via server_hostname without authentication.
Check the vendor advisory for the affected versions of aiohttp. Attack surface: server_hostname.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 3.14.1.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'aiohttp' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'aiohttp' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
aiohttpを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade aiohttp to 3.14.1ステージング環境で 3.14.1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-54275 python-aiohttp
- Ubuntu UBUNTU-CVE-2026-54275 python-aiohttp
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- web github.com