CVE-2026-39865

mediumpriority · track · 0EPSS 0.007 · 54 %ileDEEUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.73% (54th) EPSS
CVSS 5.9 · medium
Is it mine?
8 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · cert_bund · nvd

EPSS · scored 2026-10-27

Axios is a promise based HTTP client for the browser and Node.js. Starting in version 1.13.0 and prior to 1.13.2, Axios HTTP/2 session cleanup logic contains a state corruption bug that allows a malicious server to crash the client process through concurrent session closures. The vulnerability exists in the Http2Sessions.getSession() method in lib/adapters/http.js. The session cleanup logic contains a control flow error when removing sessions from the sessions array. This vulnerability is fixed in 1.13.2.

01

cvss

Technical severity, 0–10. One row per scoring source.

5.9
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · ENISA EU
v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · security-advisories@github.comexploitability 2.2 · impact 3.6
v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · OSV
v3.15.4mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: poc · Automatable: no · Technical Impact: partialcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

04

affected products (8)

Products and version ranges known to be affected.

05

advisories (2)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-1127IBM App Connect Enterprise Certified Container (axios): Schwachstelle ermöglicht Denial of ServiceDeutsch2026-04-14csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann eine Schwachstelle in IBM App Connect Enterprise Certified Container ausnutzen, um einen Denial of Service Angriff durchzuführen.

  • GHSA-qj83-cq47-w5f8Axios HTTP/2 Session Cleanup State Corruption Vulnerability2026-04-08ghsa · osvUS

    ### Summary Axios HTTP/2 session cleanup logic contains a state corruption bug that allows a malicious server to crash the client process through concurrent session closures. This denial-of-service vulnerability affects axios versions prior to 1.13.2 when HTTP/2 is enabled. ### Details The vulnerability exists in the `Http2Sessions.getSession()` method in `lib/adapters/http.js`. The session cleanup logic contains a control flow error when removing sessions from the sessions array. **Vulnerable Code:** ```javascript while (i--) { if (entries[i][0] === session) { entries.splice(i, 1); if (len === 1) { delete this.sessions[authority]; return; } } } ``` **Root Cause:** After calling `entries.splice(i, 1)` to remove a session, the original code only returned early if `len === 1`. For arrays with multiple entries, the iteration continued after modifying the array, causing undefined behavior and potential crashes when accessing shifted array indices. **Fixed Code:** ```javascript while (i--) { if (entries[i][0] === session) { if (len === 1) { delete this.sessions[authority]; } else { entries.splice(i, 1); } return; } } ``` The fix restructures the control flow to immediately return after removing a session, regardless of whether the array is being emptied or just having one element removed. This prevents continued iteration over a modified array and eliminates the state corruption vulnerability. **Affected Component:** - `lib/adapters/http.js` - Http2Sessions class, session cleanup in connection close handler ### PoC 1. Set up a malicious HTTP/2 server that accepts multiple concurrent connections from an axios client 2. Establish multiple concurrent HTTP/2 sessions with the axios client 3. Close all sessions simultaneously with precise timing 4. The flawed cleanup logic attempts to iterate over and modify the sessions array concurrently 5. This causes the client to access invalid memory locations, resulting in a process crash **Prerequisites:** - Client must use axios with HTTP/2 enabled - Client must connect to attacker-controlled HTTP/2 server - Multiple concurrent HTTP/2 sessions must be established - Server must close all sessions simultaneously with precise timing ### Impact **Who is impacted:** - Applications using axios with HTTP/2 enabled - Applications connecting to untrusted or attacker-controlled HTTP/2 servers - Node.js applications using axios for HTTP/2 requests **Impact Details:** - **Denial of Service:** Malicious server can crash the axios client process by accepting and closing multiple concurrent HTTP/2 connections simultaneously - **Availability Impact:** Complete loss of availability for the client process through crash (though service may auto-restart) - **Scope:** Impact is limited to the single client process making the requests; does not escape to affect other components or systems - **No Confidentiality or Integrity Impact:** Vulnerability only causes process crash, no information disclosure or data modification **CVSS Score:** 5.9 (Medium) **CVSS Vector:** CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H **CWE Classifications:** - CWE-400: Uncontrolled Resource Consumption - CWE-662: Improper Synchronization

06

also known as (3)

Other names and identifiers for this entity.

07

sources

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published 2026-04-08modified 2026-07-24
08

references (8)

External citations — patches, advisories, analysis.

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