Unsafe Deserialization in aiohttp (CVE-2026-34993)
Summary
Vulnerability in aiohttp (CVE-2026-34993). Data can be tampered with by attackers. Mitigation: upgrade to 3.14.0 or later.
Original description
The description as published by the source.
Summary
Using CookieJar.load() with untrusted input may allow arbitrary code execution.
Impact
Most applications using this function will be doing so with the user's own data, so this is unlikely to affect many applications.
Workaround
If an application does allow attacker controlled files to be loaded, a workaround on older releases would be to sanitise the files before loading.
Patch: https://github.com/aio-libs/aiohttp/commit/dcf40f30637e8752c76781cf6703b5a236749a00
Source: NIST National Vulnerability Database 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-2026-34993 has been found in aiohttp.
Data can be tampered with by attackers. CVSS score: 6.4/10.
What to do: upgrade aiohttp to 3.14.0 or later.
If unsure, ask your IT team or search "aiohttp CVE-2026-34993" on the vendor's site.
CVE-2026-34993 (aiohttp) — CWE-502 / CVSS v3 6.4
Attack vector: local
Patched: 3.14.0 — 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.
Unsafe deserialization (CWE-502) exists in aiohttp.
Check the vendor advisory for the affected versions of aiohttp.
Severity: Medium (CVSS 6.4/10). Data can be tampered with by attackers.
Update to 3.14.0.
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 3.14.0ステージング環境で 3.14.0 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。
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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-2026-34993 python-aiohttp
- Ubuntu UBUNTU-CVE-2026-34993 python-aiohttp
References
- advisory nvd.nist.gov
- package github.com
- patch security-advisories@github.com
- patch security-advisories@github.com
- web github.com
- web access.redhat.com
- web access.redhat.com
- web bugzilla.redhat.com
- web security.access.redhat.com
- web access.redhat.com
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- web access.redhat.com