Skip to content

CVE-2023-21529

Deserialization of Untrusted Data: Is CVE-2023-21529 real, exploitable, or a false positive? Here's the community verdict.

Community verdict: No field verdicts yet. Be the first practitioner to weigh in.

signals

public sources

Exploited in wild
Yes
CISA KEV · Apr 13, 2026
Public exploit
None known
Metasploit/EDB/PoC
Base severity
8.8 High
CVSS
Exploitation prob.
59%
FIRST EPSS
Weakness
CWE-502 · Deserialization of Untrusted Data
CWE

Confirmed exploited in the wild. Patch this first, regardless of the base score.

cisa ssvc

CISA Vulnrichment · assessed

Exploitation
Active
in the wild
Automatable
No
at scale
Technical impact
Total
on success

CISA decision, by how critical the affected system is to you:

  • low impact → Track
  • medium impact → Attend
  • high impact → Act

Track: normal patch cycle · Track*: watch closely · Attend: patch sooner · Act: patch now. About SSVC ↗

baseline read

auto · not a community verdict

Real — exploited in the wild

CISA confirms active exploitation. Treat scanner hits as true positives unless your specific version or config is unaffected.

Based on CISA KEV

Confirm or dispute →
Affected:Microsoft

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

Microsoft Exchange Server Remote Code Execution Vulnerability

NVD only has a brief summary for this one. The community fills in the real-world detail below.

Published · Added to CISA KEV (1154 days after publication)

Embed this verdict
TruePositive verdict for CVE-2023-21529
Markdown
[![TruePositive verdict](https://www.truepositive.app/cve/CVE-2023-21529/badge.svg)](https://www.truepositive.app/cve/CVE-2023-21529)
HTML
<a href="https://www.truepositive.app/cve/CVE-2023-21529"><img src="https://www.truepositive.app/cve/CVE-2023-21529/badge.svg" alt="TruePositive verdict for CVE-2023-21529"></a>

Live badge that updates automatically as the community verdict changes.

timeline

  1. CISA SSVC assessment · exploitation: active
  2. Added to CISA KEV · confirmed exploited in the wild
  3. Added to VulnCheck KEV · reported exploited in the wild
  4. Published by NVD

Score and exploit changes tracked since .

Community ground truth

Be the first practitioner to weigh in

So far this is only TruePositive's editorial baseline from public sources. Add your real-world verdict below — it becomes the signal the next person triaging this relies on.

🥇 The first 50 practitioners to contribute earn a Founding Contributor badge.

In your experience, is this finding real and exploitable?

awaiting field verdicts
Real, but not a risk here
Not a real issue

Curated baseline: TruePositive's read from public sources is Real & exploitable — a starting point, not a community verdict.

No account needed. Anonymous verdicts post as an unverified signal. Log in to make yours verified and earn reputation.

Field notes & remediation

Verdicts are the quick signal. Notes are the evidence and fixes behind them.

  • 0
    Field note · TruePositive EditorialCurated

    This is confirmed exploited in the wild. It is in the CISA KEV catalog, so attackers are actively using it, not just researchers. Patch this on priority and confirm the fix holds.

Add a field note or remediationoptional
Note type

What are you adding?

Markdown supported · minimum 20 characters.

Same weakness: CWE-502 · Deserialization of Untrusted Data.