mbed TLS up to 3.6.5/4.0.0 downgrade

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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3.7$0-$5k0.00

Summaryinfo

A vulnerability categorized as problematic has been discovered in mbed TLS up to 3.6.5/4.0.0. This issue affects some unknown processing. Executing a manipulation can lead to downgrade. The identification of this vulnerability is CVE-2026-25834. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as problematic was found in mbed TLS up to 3.6.5/4.0.0. This vulnerability affects an unknown functionality. The manipulation with an unknown input leads to a downgrade vulnerability. The CWE definition for the vulnerability is CWE-757. A protocol or its implementation supports interaction between multiple actors and allows those actors to negotiate which algorithm should be used as a protection mechanism such as encryption or authentication, but it does not select the strongest algorithm that is available to both parties. As an impact it is known to affect confidentiality. CVE summarizes:

Mbed TLS v3.3.0 up to 3.6.5 and 4.0.0 allows Algorithm Downgrade.

The advisory is available at mbed-tls.readthedocs.io. This vulnerability was named CVE-2026-25834 since 02/06/2026. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1562.010 by the MITRE ATT&CK project.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-17967). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.7
VulDB Meta Temp Score: 3.7

VulDB Base Score: 3.7
VulDB Temp Score: 3.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Downgrade
CWE: CWE-757
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

02/06/2026 CVE reserved
04/01/2026 +53 days Advisory disclosed
04/01/2026 +0 days VulDB entry created
04/01/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: mbed-tls.readthedocs.io
Status: Not defined

CVE: CVE-2026-25834 (🔒)
GCVE (CVE): GCVE-0-2026-25834
GCVE (VulDB): GCVE-100-354754
EUVD: 🔒

Entryinfo

Created: 04/01/2026 20:55
Updated: 04/01/2026 22:15
Changes: 04/01/2026 20:55 (50), 04/01/2026 22:15 (1)
Complete: 🔍
Cache ID: 216:5B6:103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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