An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before…
Priority LOW 35CWE-295Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Spoofing
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-295.
Summary
An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). A NULL algorithm parameters entry looks identical to an array of REAL (size zero) and thus the certificate is considered valid. However, if the parameters do not match in any way, then the certificate should be considered invalid.
Why it matters now
EPSS 0.01102 65th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 15
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:arm:mbed_tls:*:*:*:*:*:*:*:* | before 2.7.18; 2.8.0 to before 2.16.9; 2.17.0 to before 2.25.0 | Vulnerable | Arm |
| cpe:2.3:o:siemens:logo\!_cmr2020_firmware:*:*:*:*:*:*:*:* | before 2.2 | Vulnerable | Siemens |
| cpe:2.3:h:siemens:logo\!_cmr2020:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Siemens |
| cpe:2.3:o:siemens:logo\!_cmr2040_firmware:*:*:*:*:*:*:*:* | before 2.2 | Vulnerable | Siemens |
| cpe:2.3:h:siemens:logo\!_cmr2040:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Siemens |
| cpe:2.3:o:siemens:simatic_rtu3031c_firmware:*:*:*:*:*:*:*:* | all versions | Vulnerable | Siemens |
| cpe:2.3:h:siemens:simatic_rtu3031c:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Siemens |
| cpe:2.3:o:siemens:simatic_rtu3041c_firmware:*:*:*:*:*:*:*:* | all versions | Vulnerable | Siemens |
| cpe:2.3:h:siemens:simatic_rtu3041c:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Siemens |
| cpe:2.3:o:siemens:simatic_rtu3030c_firmware:*:*:*:*:*:*:*:* | all versions | Vulnerable | Siemens |
- cpe:2.3:a:arm:mbed_tls:*:*:*:*:*:*:*:* Versions before 2.7.18; 2.8.0 to before 2.16.9; 2.17.0 to before 2.25.0 Vulnerable ·Arm
- cpe:2.3:o:siemens:logo\!_cmr2020_firmware:*:*:*:*:*:*:*:* Versions before 2.2 Vulnerable ·Siemens
- cpe:2.3:h:siemens:logo\!_cmr2020:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Siemens
- cpe:2.3:o:siemens:logo\!_cmr2040_firmware:*:*:*:*:*:*:*:* Versions before 2.2 Vulnerable ·Siemens
- cpe:2.3:h:siemens:logo\!_cmr2040:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Siemens
- cpe:2.3:o:siemens:simatic_rtu3031c_firmware:*:*:*:*:*:*:*:* Versions all versions Vulnerable ·Siemens
- cpe:2.3:h:siemens:simatic_rtu3031c:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Siemens
- cpe:2.3:o:siemens:simatic_rtu3041c_firmware:*:*:*:*:*:*:*:* Versions all versions Vulnerable ·Siemens
- cpe:2.3:h:siemens:simatic_rtu3041c:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Siemens
- cpe:2.3:o:siemens:simatic_rtu3030c_firmware:*:*:*:*:*:*:*:* Versions all versions Vulnerable ·Siemens
Show 5 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:h:siemens:simatic_rtu3030c:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Siemens |
| cpe:2.3:o:siemens:simatic_rtu3000c_firmware:*:*:*:*:*:*:*:* | all versions | Vulnerable | Siemens |
| cpe:2.3:h:siemens:simatic_rtu3000c:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Siemens |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Debian |
- cpe:2.3:h:siemens:simatic_rtu3030c:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Siemens
- cpe:2.3:o:siemens:simatic_rtu3000c_firmware:*:*:*:*:*:*:*:* Versions all versions Vulnerable ·Siemens
- cpe:2.3:h:siemens:simatic_rtu3000c:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Siemens
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2020-36478
- 2026-10-03 Alias added: GHSA-8xrj-2854-7x44
References
Advisory 5
- https://github.com/ARMmbed/mbedtls/releases/tag/v2.25.0
- https://github.com/ARMmbed/mbedtls/releases/tag/v2.16.9
- https://github.com/ARMmbed/mbedtls/releases/tag/v2.7.18
- [debian-lts-announce] 20211123 [SECURITY] [DLA 2826-1] mbedtls security update
- [debian-lts-announce] 20221225 [SECURITY] [DLA 3249-1] mbedtls security update
Sources
- CVE-2020-36478 · CVE Program
- CVE-2020-36478 · NVD
- FIRST EPSS
- GHSA-8xrj-2854-7x44 · GitHub Advisory Database · CC BY 4.0
- CVE-2020-36478 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences