Vulnerability report

Exploitation Attempts Observed Confirmed Confidence Not in CISA KEV

CVE-2026-90436

Apache Axis 1.x (EOL) Deserialization

Apache Axis 1.x (EOL · 0 to <= 1.4

Watch CVE-2026-90436 Browse KEV feed
Severity
CVSS 9.8 · Critical
Confidence
Confirmed
Exploit status
Exploitation Attempts Observed in the Wild
EPSS
0.6%
First observed
12 Nov 2026
Last observed
12 Nov 2026

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-90436 is an unauthenticated vulnerability affecting Apache Axis 1.x (EOL.

Have exploitation attempts been observed?

Yes. Previdian sensors have observed 2 exploitation attempts, 1 unique attacker IP, and 1 country targeting CVE-2026-90436. First observed Nov 12, 2026. Confidence is confirmed.

Who is affected?

Apache Axis 1.x (EOL, including 0 to <= 1.4 and affected before 41f3b4e8d04e310ca81f86b92630ab2c11d608bd.

What should we do?

Patch immediately, validate internet-facing exposure, and monitor for matching requests.

Overview

Apache Axis 1.x (EOL) Deserialization

** UNSUPPORTED WHEN ASSIGNED ** Deserialization of an inbound SOAP fault in Apache Axis 1.x allows unauthenticated remote class instantiation. When a SOAP carries a element, Axis loads the named class and, if a String element is also present, instantiates it through its String constructor before checking that it is an AxisFault. Loading alone runs the class's static initializer. With a suitable class on the application's classpath this leads to remote code execution. The fault is parsed while the engine resolves the target service, before any per-service handler chain runs, so authentication handlers configured on a service do not protect against it. This affects all Apache Axis 1.x versions through 1.4.

As Axis 1 has been EOL we recommend you migrate to a different SOAP engine, such as Apache Axis 2/Java. Alternatively you could use a build of Axis with the patch from https://github.com/apache/axis-axis1-java/commit/41f3b4e8d04e310ca81f86b92630ab2c11d608bd applied. The Apache Axis project does not expect to create an Axis 1.x release fixing this problem.

Apache Software Foundation Affected
Apache Axis 1.x (EOL) axis:axis
Through 1.4
Apache Software Foundation Affected
Apache Axis 1.x (EOL) org.apache.axis:axis
Through 1.4
Apache Software Foundation Affected
Apache Axis 1.x (EOL)
Before 41f3b4e8d04e310ca81f86b92630ab2c11d608bd
View vendor advisory (opens in new tab)
Published
06 Nov 2026
Attempts Observed Since
12 Nov 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

apache

CVE References

  • CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2026-90436
  • Apache Mailing List lists.apache.org · Vendor Advisory https://lists.apache.org/thread.html/8slf0j9gz35z56t0glt5h0ncwlbn4bdz
  • GitHub — apache/axis-axis1-java github.com · Patch https://github.com/apache/axis-axis1-java/commit/41f3b4e8d04e310ca81f...

Exploitation evidence

Evidence of exploitation attempts

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploitation Attempts Observed in the Wild

Previdian

Recorded 12 Nov 2026

Previdian sensors observed exploitation attempts targeting this vulnerability.

Exploitation Attempts Observed

Previdian sensor

First observed 12 Nov 2026

Previdian sensors observed exploitation attempts targeting this vulnerability.

Proof of concept available

GitHub

Recorded 10 Nov 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
Previdian First 2026-11-12 10:13 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

Previdian Sensor Observations

Previdian sensor observations are exploitation attempts targeting this vulnerability. They do not show that the target was vulnerable or that the attempt succeeded. The cards and chart show volume, unique attackers, and daily activity.

2

Attempts observed

1

Unique attacker IPs

1

Attacker countries

IN

1

Sensors observed

CVE-2026-90436 exploitation attempts over the last 7 days

Daily events observed by Previdian sensors

Updated 12 Nov 2026

0
0
0
0
0
0
2
6 Nov 7 Nov 8 Nov 9 Nov 10 Nov 11 Nov 12 Nov

First observed 12 Nov 2026 · Last observed 12 Nov 2026

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Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
1
1
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Attacker IP Indicators

Attacker IP indicators observed · available in Pro and Enterprise.

Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.

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Risk and context

Severity, weaknesses, and research context

CVSS v3.1

9.8 Critical

Potential damage if exploited. Separate from whether attackers are using it.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

0.6%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') CWE-470

Recent mention · The Hacker News

New N-central Exploits Work Against Patched Servers, Enable Root RCE and Windows SYSTEM Access

Ravie LakshmananNov 12, 2026Vulnerability / Cyber Attack N-able on Thursday said it's investigating a new public disclosure containing claims of additional vulnerabilities in on-premise versions of N-central running version 2026.4.1 HF2. "Based on our initial review, the...

Read full advisory

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

fixedbyreboot/CVE-2026-90436-POC

github · Created 2026-11-10 06:45:30 UTC · 0 stars · AI assessment 96%

POC for CVE-2026-90436 - unauthenticated remote class instantiation in Apache Axis 1.x via SOAP fault exceptionName, bypassing configured auth handlers. EOL software, no fix exists.

Timeline

From disclosure to observed exploitation attempts

  1. 10:13 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party report of exploitation attempts

  2. 08:24 UTC

    Indicator of compromise added

    Indicators of compromise recorded

  3. 08:24 UTC

    Observed by Previdian sensors

    Previdian sensors observed exploitation attempts targeting this vulnerability.

  4. 06:45 UTC

    Public PoC available

    Public proof-of-concept code published

  5. 14:20 UTC

    Added to the Previdian watchlist

    Pro and Enterprise Watch users had 3 days of early warning before Previdian KEV.

  6. 15:37 UTC

    CVE published

    Vulnerability disclosed publicly

  7. 19:51 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-90436

Sample API response 
{
  "cve_id": "CVE-2026-90436",
  "confidence": "Confirmed",
  "cvss_score": 9.8,
  "cvss_estimated": false,
  "epss_score": 0.00567,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 2, "sensors": 1 }
}