aiohttp: Improper Handling of Highly Compressed Data (Data Amplification)
CVE-2025-69223 is a high-severity improper handling of highly compressed data (data amplification) vulnerability in aiohttp from Aio-libs, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected aiohttp versions: < 3.13.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.58% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of aiohttp you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (github.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | CNA (github.com) |
| CVSS 3.1 | 7.5 | High | CNA |
Official description
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Versions 3.13.2 and below allow a zip bomb to be used to execute a DoS against the AIOHTTP server. An attacker may be able to send a compressed request that when decompressed by AIOHTTP could exhaust the host's memory. This issue is fixed in version 3.13.3.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Handling of Highly Compressed Data (Data Amplification)
The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.
More Improper Handling of Highly Compressed Data (Data Amplification) vulnerabilities (CWE-409)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
- access.redhat.com/errata/RHSA-2026:10184
- access.redhat.com/errata/RHSA-2026:1249
- access.redhat.com/errata/RHSA-2026:1497
- access.redhat.com/errata/RHSA-2026:1506
- access.redhat.com/errata/RHSA-2026:1596
- access.redhat.com/errata/RHSA-2026:1599
- access.redhat.com/errata/RHSA-2026:1609
- access.redhat.com/errata/RHSA-2026:19712
- access.redhat.com/errata/RHSA-2026:2106
- access.redhat.com/errata/RHSA-2026:2695
- access.redhat.com/errata/RHSA-2026:3461
- access.redhat.com/errata/RHSA-2026:3462
- access.redhat.com/errata/RHSA-2026:3713
- access.redhat.com/errata/RHSA-2026:37275
- access.redhat.com/errata/RHSA-2026:3782
Other vulnerabilities in aiohttp
- 8.7 High severity
- 8.7 High severity
- 8.3 High severity
- 8.2 High severity
- 7.5 High severity
- 8.7 High severity
Recent Improper Handling of Highly Compressed Data (Data Amplification) vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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