CVE-2025-48965VulnerabilityPublished 20 Jul 2025Updated 3 Nov 2025

CVE-2025-48965: Mbed mbedtls · Incorrect Behavior Order

Affects Mbed mbedtlsSource CVE Database V5

Not known to be exploited · CVSS 4.0 Medium : upgrade to 3.6.4 when convenient.

Data as of 26 Oct 2026, 08:30 UTC

CVSS 3.1 base score

4.0Medium

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 47% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.6.4

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

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

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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
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: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
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: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 20 Jul 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 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

Upgrade mbed-tls/mbedtls to 3.6.4.

Affected software

Product	Affected	Fixed in
GitHubmbed-tls/mbedtls`pkg:github/mbed-tls/mbedtls`Other threats	Affected <3.6.4	Fixed in 3.6.4

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

European organizations should implement the following specific mitigation steps: 1) Inventory all systems and devices using Mbed TLS to identify those running versions prior to 3.6.4. 2) Monitor official Mbed TLS channels and security advisories for the release of patches addressing CVE-2025-48965 and apply updates promptly. 3) Where immediate patching is not feasible, implement network-level protections such as intrusion detection/prevention systems (IDS/IPS) to monitor and block anomalous traffic targeting vulnerable services. 4) Employ robust input validation and error handling in applications interfacing with Mbed TLS to reduce the risk of triggering the NULL pointer dereference. 5) Conduct thorough testing of embedded and IoT devices to ensure stability and resilience against malformed ASN.1 data inputs. 6) Engage with device vendors to confirm patch availability and deployment timelines. 7) Consider network segmentation to isolate vulnerable devices and limit exposure. These measures go beyond generic advice by focusing on embedded device management, vendor coordination, and network controls tailored to the nature of this vulnerability.

Description

Mbed TLS before 3.6.4 has a NULL pointer dereference because mbedtls_asn1_store_named_data can trigger conflicting data with val.p of NULL but val.len greater than zero.

Impact

For European organizations, the primary impact of CVE-2025-48965 is the potential for denial of service in systems using vulnerable versions of Mbed TLS. This is particularly relevant for industries relying on embedded devices, IoT infrastructure, and secure communications where Mbed TLS is integrated. Disruptions could affect critical services, industrial control systems, and networked devices, leading to operational downtime and potential safety risks. Although the vulnerability does not compromise confidentiality or integrity, availability impacts can cause cascading effects in tightly coupled systems. Organizations in sectors such as manufacturing, automotive, healthcare, and telecommunications may face increased risk due to their reliance on embedded cryptographic libraries. The medium severity rating suggests that while exploitation is not trivial, the consequences of successful exploitation warrant proactive mitigation to maintain service continuity.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Nov 2025, 01:31 UTC

WeaknessesCWE-696

Technical details

References

Community reviews

Related threats