CyberSecBulletin
CVE-2026-34993NVD status: Modified

aiohttp: Deserialization of Untrusted Data

Published Updated By the CyberSecBulletin desk

CVE-2026-34993 is a high-severity deserialization of untrusted data vulnerability in aiohttp from Aio-libs, with a CVSS 3.1 base score of 7.3 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. Affected aiohttp versions: < 3.14.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.18% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of aiohttp you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
Aio-libsaiohttp< 3.14.0Not stated
Red HatRed Hat Ansible Automation Platform 2.5 for RHEL 8Not specified in the recordNot stated
Red HatRed Hat Ansible Automation Platform 2.5 for RHEL 9Not specified in the recordNot stated
Red HatRed Hat Ansible Automation Platform 2.6 for RHEL 9Not specified in the recordNot stated
Red HatRed Hat Satellite 6.16 for RHEL 8Not specified in the recordNot stated
Red HatRed Hat Satellite 6.16 for RHEL 9Not specified in the recordNot stated
Red HatRed Hat Satellite 6.17 for RHEL 9Not specified in the recordNot stated
Red HatRed Hat Satellite 6.18 for RHEL 9Not specified in the recordNot stated
Red HatRed Hat Satellite 6.19 for RHEL 9Not specified in the recordNot stated
Red HatRed Hat AI Inference Server 3.3Not specified in the recordNot stated
Red HatRed Hat Ansible Automation Platform 2.5Not specified in the recordNot stated
Red HatRed Hat Ansible Automation Platform 2.6Not specified in the recordNot stated
Red HatRed Hat Ansible Automation Platform 2.7Not specified in the recordNot stated
Red HatRed Hat Discovery 2Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux AI 3.3Not specified in the recordNot stated
Red HatRed Hat Migration Toolkit for Applications 8.2Not specified in the recordNot stated
Red HatRed Hat OpenShift AI 2.25Not specified in the recordNot stated
Red HatRed Hat OpenShift AI 3.3Not specified in the recordNot stated
Red HatRed Hat OpenShift AI 3.4Not specified in the recordNot stated
Red HatExploit IntelligenceNot specified in the recordNot stated
Red HatLightspeed CoreNot specified in the recordNot stated
Red HatOpenShift LightspeedNot specified in the recordNot stated
Red HatRed Hat AI Inference ServerNot specified in the recordNot stated
Red HatRed Hat Ansible Automation Platform 2Not specified in the recordNot stated
Red HatRed Hat Ansible Automation Platform Ansible Core 2Not specified in the recordNot stated

Version data comes from the organisation that assigned the CVE; 5 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.16.4MediumCNA (github.com)
CVSS 3.17.3HighNVD
CVSS 3.17.2HighCNA

Official description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.14.0, using ``CookieJar.load()`` with untrusted input may allow arbitrary code execution. Most applications using this function will be doing so with the user's own data, so this is unlikely to affect many applications. Version 3.14.0 patches the issue. If an application does allow attacker controlled files to be loaded, a workaround on older releases would be to sanitize the files before loading.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Deserialization of Untrusted Data

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

How developers prevent this class of flaw

  • If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
  • When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
  • Explicitly define a final object() to prevent deserialization.

More Deserialization of Untrusted Data vulnerabilities (CWE-502)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in aiohttp

All aiohttp vulnerabilities

Recent Deserialization of Untrusted Data vulnerabilities

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