CVE-2026-21525
NULL Pointer Dereference: Is CVE-2026-21525 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
Confirmed exploited in the wild. Patch this first, regardless of the base score.
cisa ssvc
CISA Vulnrichment · assessed
CISA decision, by how critical the affected system is to you:
- low impact → Track
- medium impact → Track
- high impact → Attend
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 →CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Null pointer dereference in Windows Remote Access Connection Manager allows an unauthorized attacker to deny service locally.
NVD only has a brief summary for this one. The community fills in the real-world detail below.
References
Published · Added to CISA KEV (same day)
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timeline
- CISA SSVC assessment · exploitation: active
- Published by NVD
- Added to VulnCheck KEV · reported exploited in the wild
- Added to CISA KEV · confirmed exploited in the wild
Score and exploit changes tracked since .
Community ground truth
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In your experience, is this finding real and exploitable?
awaiting field verdictsCurated baseline: TruePositive's read from public sources is Real & exploitable — a starting point, not a community verdict.
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Field notes & remediation
Verdicts are the quick signal. Notes are the evidence and fixes behind them.
- 0
Microsoft Windows NULL Pointer Dereference Vulnerability — Microsoft Windows Remote Access Connection Manager contains a NULL pointer dereference that could allow an unauthorized attacker to deny service locally. Listed in the CISA KEV catalog (added 2026-02-10) — confirmed exploited in the wild, not theoretical. FIRST EPSS puts the chance of exploitation in the next 30 days at ~5%. Treat it as real and prioritize remediation over triage.
- 0
Required action for Microsoft Windows: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. CISA set a federal remediation due date of 2026-03-03. After patching, verify the vulnerable path is no longer reachable before closing the finding.
Add a field note or remediationoptional
Related CVEs
Same weakness: CWE-476 · NULL Pointer Dereference.
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Server or client applications that call the SSL_check_chain() function during or after a TLS 1.3 handshake may crash due to a NULL pointer dereference as a result of incorrect handling of the "signature_algorithms_cert" TLS extension. The crash occurs if an invalid or unrecognised signature algorithm is received from the peer. This could be exploited by a malicious peer in a Denial of Service attack. OpenSSL version 1.1.1d, 1.1.1e, and 1.1.1f are affected by this issue. This issue did not affect OpenSSL versions prior to 1.1.1d. Fixed in OpenSSL 1.1.1g (Affected 1.1.1d-1.1.1f).
- CVE-2019-5010HIGH 7.5EPSS 21%
An exploitable denial-of-service vulnerability exists in the X509 certificate parser of Python.org Python 2.7.11 / 3.6.6. A specially crafted X509 certificate can cause a NULL pointer dereference, resulting in a denial of service. An attacker can initiate or accept TLS connections using crafted certificates to trigger this vulnerability.
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