VulnerabilityPublished 21 Aug 2025Updated 13 Feb 2026

CVE-2025-55229: Microsoft Windows 10 Version 1507 · Improper Verification of Cryptographic Signature

Affects Microsoft Windows 10 Version 1507Source CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 42% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C

Base metrics

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Temporal metrics

Exploit Code Maturity: Unproven
Remediation Level: Official Fix
Report Confidence: Confirmed

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.
Exploit Code Maturity: Unproven: No exploit code is available, or an exploit is theoretical.
Remediation Level: Official Fix: A complete vendor solution is available. Either the vendor has issued an official patch, or an upgrade is available.
Report Confidence: Confirmed: Detailed reports exist, or functional reproduction is possible (functional exploits may provide this). Source code is available to independently verify the assertions of the research, or the author or vendor of the affected code has confirmed the presence of the vulnerability.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 21 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Microsoft Windows 10 Version 1507	Affected =10.0.10240.0	Fixed in–

AI-suggested

To mitigate CVE-2025-55229, European organizations should prioritize upgrading all systems running Windows 10 Version 1507 to the latest supported Windows 10 or Windows 11 versions where this vulnerability is patched. If immediate upgrading is not feasible, organizations should implement network-level controls such as strict firewall rules to limit exposure of vulnerable systems to untrusted networks. Deploy network intrusion detection systems (NIDS) to monitor for anomalous spoofing or certificate-related attacks. Enforce strict certificate validation policies and consider using additional layers of cryptographic verification or multi-factor authentication to reduce reliance on vulnerable certificate checks. Regularly audit and inventory systems to identify any legacy Windows 10 1507 installations and remove or isolate them from critical network segments. Engage with Microsoft support channels to obtain any out-of-band patches or mitigations if available. Additionally, educate IT staff about the risks of improper certificate verification and ensure incident response plans include scenarios involving spoofing attacks. Finally, maintain updated threat intelligence feeds to detect emerging exploits targeting this vulnerability.

Description

Improper verification of cryptographic signature in Windows Certificates allows an unauthorized attacker to perform spoofing over a network.

Impact

For European organizations, the primary impact of CVE-2025-55229 lies in the potential compromise of confidentiality through spoofing attacks that exploit improper cryptographic signature verification. This can lead to unauthorized interception or manipulation of sensitive communications, especially in sectors relying heavily on certificate-based authentication such as finance, healthcare, and government services. The vulnerability does not affect integrity or availability directly, but successful spoofing could facilitate further attacks or data breaches. Organizations using Windows 10 Version 1507, particularly in legacy systems or isolated environments where upgrades are delayed, face increased risk. The ease of exploitation over a network without authentication or user interaction raises concerns for enterprise networks, remote access solutions, and VPNs that depend on Windows certificate validation. Although no known exploits exist currently, the medium severity rating and network exposure warrant immediate attention to prevent potential exploitation. Failure to address this vulnerability could result in loss of trust in cryptographic protections and increased risk of data leakage or fraud.

CWE-347Improper Verification of Cryptographic Signature (opens in a new tab)
Base weaknessOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
OWASP Cheat Sheets
XML Security (opens in a new tab)
REST Security (opens in a new tab)
JSON Web Token for Java (opens in a new tab)
REST Assessment (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.2 (opens in a new tab)
V3.5.3 (opens in a new tab)
V13.2.6 (opens in a new tab)
Attack patterns
Padding Oracle Crypto Attack (opens in a new tab)
Signature Spoofing by Improper Validation (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2025-55229 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 14 Feb 2026, 10:57 UTC

WeaknessesCWE-347

Technical details

References

Community reviews

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