Vulnerability in aiohttp (CVE-2026-54277)
Summary
Vulnerability in aiohttp (CVE-2026-54277). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 3.14.1 or later.
Original description
The description as published by the source.
Summary
It is possible to bypass the max_line_size check in parts of an HTTP request in the C parser.
Impact
If using the optimised C parser (the default in pre-built wheels), then an attacker may be able to send oversized lines through the HTTP parser and use an excessive amount of memory, potentially leading to DoS.
Patch: https://github.com/aio-libs/aiohttp/commit/5ab61bb4cd88f19b712f12c7c9295fe262bf804d
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-2026-54277 has been found in aiohttp.
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-2026-54277" on the vendor's site.
CVE-2026-54277 (aiohttp) — CWE-770 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
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-770) exists in aiohttp.
Check the vendor advisory for the affected versions of aiohttp.
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
-
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
- Ubuntu UBUNTU-CVE-2026-54277 python-aiohttp
References
- patch security-advisories@github.com
- patch security-advisories@github.com
- web github.com