CVE-2026-39865Public exploitNetwork attack vector

Client process crash via concurrent session cleanup

Published Apr 8, 2026 · Updated Apr 8, 2026

Improper synchronization in Axios 1.13.0 through 1.13.1 allows remote attackers to crash a Node.js client through HTTP/2 session closures. Http2Sessions.getSession() splices a closed session from its array but continues iterating shifted entries, corrupting cleanup state. Exploitation requires HTTP/2 to be enabled, multiple sessions to an attacker-controlled server, and precisely timed simultaneous closures; impact stays within the client process.

CVSS severity5.9
Medium
EPSS probability0.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper synchronization in Axios 1.13.0 through 1.13.1 allows remote attackers to crash a Node.js client through HTTP/2 session closures. Http2Sessions.getSession() splices a closed session from its array but continues iterating shifted entries, corrupting cleanup state. Exploitation requires HTTP/2 to be enabled, multiple sessions to an attacker-controlled server, and precisely timed simultaneous closures; impact stays within the client process.

The record

CVE
CVE-2026-39865
Published
Apr 8, 2026
Updated
Apr 8, 2026
Vendor
Axios
Product
Axios
Classifications
CWE-400, CWE-662, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.13.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Axios · Axiosversion=< 1.13.2

Published CVSS scores

5.9GitHubCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
CWE-662Improper Synchronization
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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