CVE-2025-65494VulnerabilityPublished 24 Nov 2025

CVE-2025-65494: n/a

Source CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 17% 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:N/I:N/A:H

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

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: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 24 Nov 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 2026-10-25.

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 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

AI-suggested

To mitigate CVE-2025-65494, organizations should prioritize updating libcoap to a patched version once it becomes available from the maintainers. In the interim, applying custom patches or workarounds to add NULL checks after sk_GENERAL_NAME_value() calls can prevent crashes. Network-level mitigations include filtering and validating incoming certificates to block malformed or suspicious X.509 certificates before they reach vulnerable devices. Implementing strict certificate validation policies and using certificate pinning where feasible can reduce exposure. Monitoring logs and network traffic for unusual certificate-related errors or crashes can help detect exploitation attempts early. For critical deployments, consider isolating vulnerable devices from untrusted networks and employing intrusion detection systems tuned for CoAP anomalies. Vendors and integrators should review their firmware and software supply chains to ensure updated libcoap versions are deployed promptly. Finally, raising awareness among IoT device operators about this vulnerability will facilitate faster response and remediation.

Description

CVE-2025-65494 is a high-severity vulnerability in libcoap 4.3.5, where a NULL pointer dereference occurs in the get_san_or_cn_from_cert() function when processing crafted X.509 certificates. This flaw allows remote attackers to cause a denial of service (DoS) without requiring authentication or user interaction. The vulnerability arises because sk_GENERAL_NAME_value() can return NULL, which is not properly handled, leading to a crash. There are no known exploits in the wild yet, but the CVSS score of 7.5 indicates a significant risk. European organizations using libcoap in IoT or constrained device environments should be particularly vigilant. Mitigation involves applying patches once available and implementing strict certificate validation and input sanitization.

Impact

For European organizations, the primary impact of CVE-2025-65494 is the potential denial of service on devices and services using libcoap 4.3.5. This can lead to outages in IoT deployments, industrial control systems, and smart infrastructure that depend on CoAP for lightweight communication. Disruptions could affect utilities, manufacturing, transportation, and smart city applications, causing operational downtime and potential safety risks. Since the vulnerability does not compromise confidentiality or integrity, data breaches are unlikely; however, availability loss can have cascading effects on dependent systems. The lack of authentication or user interaction requirements means attackers can remotely trigger the DoS, increasing the threat surface. European critical infrastructure operators and enterprises with extensive IoT deployments may face increased risk of service interruptions, impacting business continuity and regulatory compliance. Additionally, the vulnerability could be leveraged as part of larger attack campaigns targeting IoT ecosystems, amplifying its impact.

Summary

CVE-2025-65494 identifies a NULL pointer dereference vulnerability in the get_san_or_cn_from_cert() function within the src/coap_openssl.c file of libcoap version 4.3.5. Libcoap is a widely used open-source implementation of the Constrained Application Protocol (CoAP), primarily deployed in IoT and constrained network environments. The vulnerability occurs when the function attempts to extract Subject Alternative Name (SAN) or Common Name (CN) fields from an X.509 certificate. Specifically, the function calls sk_GENERAL_NAME_value(), which can return NULL if the certificate is crafted maliciously. The code does not check for this NULL return value before dereferencing it, resulting in a NULL pointer dereference and subsequent application crash. This leads to a denial of service condition, as the affected libcoap-based service or device becomes unresponsive or terminates unexpectedly. The vulnerability is remotely exploitable over the network without any authentication or user interaction, increasing its risk profile. Although no public exploits have been reported yet, the CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) reflects a high severity due to the ease of exploitation and impact on availability. The flaw is categorized under CWE-476 (NULL Pointer Dereference), a common programming error that can cause crashes or unpredictable behavior. Since libcoap is embedded in many IoT devices and constrained environments, this vulnerability could disrupt critical services relying on CoAP for communication, such as smart meters, industrial sensors, and building automation systems.

CWE-476NULL Pointer Dereference (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #13OWASP Top 10 A10:2025: Mishandling of Exceptional Conditions (opens in a new tab)
The product dereferences a pointer that it expects to be valid but is NULL.
Implementation
For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
Requirements
Select a programming language that is not susceptible to these issues.
Implementation
Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
OWASP Cheat Sheets
Logging (opens in a new tab)
Error Handling (opens in a new tab)
OWASP ASVS 4.0.3
V11.1.7 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 1 Dec 2025, 14:42 UTC

WeaknessesCWE-476

Technical details

References

Community reviews

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