⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● High · CVSS 7.5

How to Fix CVE-2026-25639: Denial of Service in axios

Other vulnerabilities in the same area that are worth patching alongside this one:

*By Sai Kiran Pandrala*

⚡ At a glance
SeverityCVSS 7.5 - High
Actively exploited?Not currently listed in CISA KEV
Affected>= 1.0.0, < 1.13.5, < 0.30.3
Fixed inversions
Type (CWE)CWE-754: Improper Check for Unusual or Exceptional Conditions

What is CVE-2026-25639?

CVE-2026-25639 is a denial of service flaw in axios. A crafted request triggers a code path that crashes or hangs the service, taking the product offline for legitimate users. Vendor description: Axios is a promise based HTTP client for the browser and Node.js. Prior to versions 0.30.3 and 1.13.5, the mergeConfig function in axios crashes with a TypeError when processing configuration objects containing __proto__ as an own property.

Why this CVE matters

Denial-of-service flaws in a network gateway or firewall have an outsize operational impact. A single packet that reboots an inline device takes down everything behind it, which is why even non-RCE bugs on these products warrant priority patching.

For deployments of axios that have been exposed to the public internet during the disclosure window, the operating assumption should be that scanning has already happened. Even where exploitation has not been publicly observed, scanning for the vulnerable fingerprint is cheap and routine. Patching closes the door; log review and credential rotation close out the rest of the response.

Am I affected?

You are affected if your installation matches any of these version ranges:

Check your installed version against the list above. If you cannot determine the version, treat the system as affected and follow the upgrade path below.

Open axios's About dialog or run the vendor-documented version-check command. Compare the result against the affected ranges in the advisory.

How to fix CVE-2026-25639

  1. Read the vendor advisory in full: https://github.com/axios/axios/security/advisories/GHSA-43fc-jf86-j433
  2. Upgrade axios to the patched build listed in the vendor advisory.
  3. Back up the configuration (and database, where applicable) before upgrading.
  4. Apply the patch in a maintenance window. For HA pairs, upgrade the standby node first, fail over, then upgrade the former primary.
  5. Restart the affected service so the patched binary loads, then verify the new version (see verification section).

Patched-version commands

Vendor advisory: https://github.com/axios/axios/security/advisories/GHSA-43fc-jf86-j433

Affected: axios: >= 1.0.0, < 1.13.5

Patched in: <patched-version-from-advisory>


# Check the current iOS / iPadOS build (libimobiledevice).
ideviceinfo -k ProductVersion
ideviceinfo -k BuildVersion

# Trigger the user-facing update flow on-device:
# Settings -> General -> Software Update -> Download and Install
# Confirm the build matches the fixed-in build from https://github.com/axios/axios/security/advisories/GHSA-43fc-jf86-j433


# Vendor advisory: https://github.com/axios/axios/security/advisories/GHSA-43fc-jf86-j433
# Fleet check via Microsoft Intune (Graph PowerShell).
Connect-MgGraph -Scopes Device.Read.All
Get-MgDeviceManagementManagedDevice -Filter "operatingSystem eq 'iOS'" |
  Where-Object { $_.OSVersion -lt "<patched-version-from-advisory>" } |
  Select-Object DeviceName, OSVersion, UserPrincipalName

Verify the fix landed


# Vendor advisory: https://github.com/axios/axios/security/advisories/GHSA-43fc-jf86-j433
# Post-patch verification (replace <service> with the real service unit).
journalctl -u <service> --since "10 minutes ago"
dmesg --since "10 minutes ago"

# Re-scan with your vulnerability scanner (Nessus, Qualys, Tenable, OpenVAS).
# It should no longer flag CVE-2026-25639 on the patched target.

If you cannot patch immediately

Front the service with rate limiting and drop malformed packets at a load balancer or IPS. Patch to remove the underlying crash condition.

How to verify the fix worked

If your installation was internet-reachable during the disclosure window, treat log review as part of the remediation rather than an optional follow-up. Look for repeated service restarts, crash logs from the affected daemon, and core files generated around the time of any anomalous traffic. A memory-corruption flaw used for exploitation often leaves a trail of failed attempts before the successful one.

Frequently asked questions

Is CVE-2026-25639 being exploited in the wild?

Public exploitation has not been confirmed by CISA at the time of writing. Treat the patch as time-sensitive anyway; reports often lag actual abuse.

Will a WAF or IDS rule fully mitigate CVE-2026-25639?

No. Network-layer filters can reduce noise and slow opportunistic scanners, but they will not stop a determined attacker. The vendor patch is the only durable fix.

How long should I plan for the upgrade?

Typical vendor-documented upgrade windows for axios run from a few minutes to under an hour depending on cluster size. Test in a staging environment first and follow the vendor's documented HA upgrade order.

References

*This guide was assembled from the official vendor advisory, the NVD record, and the CISA KEV catalog entry on 2026-05-25. Always confirm against the vendor advisory before applying changes in production.*