How severe is CVE-2024-23829?

CVE-2024-23829 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2024-23829?

CVE-2024-23829 affects the following packages: aiohttp (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2024-23829?

Update aiohttp to 3.9.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-23829 is resolved across your whole dependency graph.

How do I detect CVE-2024-23829 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for aiohttp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2024-23829 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2024-23829 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2024-23829, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2024-23829?

CVE-2024-23829 has an EPSS (Exploit Prediction Scoring System) score of 1.0%, placing it in the 64th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2024-23829?

CVE-2024-23829 is classified as CWE-444 (CWE-444). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2024-23829 published, and has it been updated?

CVE-2024-23829 was published on January 29, 2024 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

MEDIUM severity

CVE-2024-23829 — aiohttp

MEDIUMFix: aio-libs/aiohttp@33ccdfb

CVE-2024-23829 is a medium-severity (CVSS 6.5) CWE-444 vulnerability in aiohttp. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for aiohttp — see the affected versions and patch details below.

aiohttp's HTTP parser (the python one, not llhttp) still overly lenient about separators

Also known asGHSA-8qpw-xqxj-h4r2PYSEC-2024-26

Published

Jan 29, 2024

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2024-23829.

EPSS Exploitation Probability

via FIRST.org ↗

1.0%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs64th percentile — riskier than 64% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐍aiohttp

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Summary

Security-sensitive parts of the Python HTTP parser retained minor differences in allowable character sets, that must trigger error handling to robustly match frame boundaries of proxies in order to protect against injection of additional requests. Additionally, validation could trigger exceptions that were not handled consistently with processing of other malformed input.

Details

These problems are rooted in pattern matching protocol elements, previously improved by PR #3235 and GHSA-gfw2-4jvh-wgfg:

The expression HTTP/(\d).(\d) lacked another backslash to clarify that the separator should be a literal dot, not just any Unicode code point (result: HTTP/(\d)\.(\d)).
The HTTP version was permitting Unicode digits, where only ASCII digits are standards-compliant.
Distinct regular expressions for validating HTTP Method and Header field names were used - though both should (at least) apply the common restrictions of rfc9110 token.

PoC

GET / HTTP/1ö1 GET / HTTP/1.𝟙 GET/: HTTP/1.1 Content-Encoding?: chunked

Impact

Primarily concerns running an aiohttp server without llhttp:

behind a proxy: Being more lenient than internet standards require could, depending on deployment environment, assist in request smuggling.
directly accessible or exposed behind proxies relaying malformed input: the unhandled exception could cause excessive resource consumption on the application server and/or its logging facilities.

Patch: https://github.com/aio-libs/aiohttp/pull/8074/files

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`aiohttp`	all versions	3.9.2`pip install --upgrade 'aiohttp==3.9.2'`

Affected Products

2 products · 2 configurations

Application

aiohttpaiohttp

< 3.9.2

range

fedorafedoraproject

1 version

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

aiohttp is an asynchronous HTTP client/server framework for asyncio and …

github.comNVDFeb 2024

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for aiohttp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update aiohttp to 3.9.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-23829 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

Product	Fixed in	Advisory
Red Hat Ansible Automation Platform 2.4 for RHEL 8	`automation-controller-0:4.5.5-2.el8ap`	RHSA-2024:1640
Red Hat Satellite 6.14 for RHEL 8	`python-aiohttp-0:3.9.2-0.1.el8pc`	RHSA-2024:1536
Red Hat Satellite 6.15 for RHEL 8	`python-aiohttp-0:3.9.2-1.el8pc`	RHSA-2024:2010
RHUI 4 for RHEL 8	`python-aiohttp-0:3.9.2-1.el8ui`	RHSA-2024:1878

Frequently Asked Questions

### Summary Security-sensitive parts of the *Python HTTP parser* retained minor differences in allowable character sets, that must trigger error handling to robustly match frame boundaries of proxies in order to protect against injection of additional requests. Additionally, validation could trigger exceptions that were not handled consistently with processing of other malformed input. ### Details These problems are rooted in pattern matching protocol elements, previously improved by PR #3235 and GHSA-gfw2-4jvh-wgfg: 1. The expression `HTTP/(\d).(\d)` lacked another backslash to clarify that

O3 Security · Impact-Aware SCA

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