In Mbed TLS 3.6.1 through 3.6.3 before 3.6.4, a timing discrepancy in block cipher…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
In Mbed TLS 3.6.1 through 3.6.3 before 3.6.4, a timing discrepancy in block cipher padding removal allows an attacker to recover the plaintext when PKCS#7 padding mode is used.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA mbedtls (Mbed) Fixed in 3.6.4
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
Mbed mbedtls 3.6.4
3 records Highest priority Priority MEDIUM 1 MEDIUM, 2 LOW
Other records, highest priority first
- TI-2025-30320 Use after free in mbedtlsPriority MEDIUM 48
- TI-2025-31103 NULL pointer dereference in mbedtlsPriority LOW 34
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2025-49087
- 2026-10-03 Alias added: GHSA-fmjv-q9m9-j657
References
More Mbed vulnerabilities
- TI-2025-32620 Mbed TLS before 3.6.4 has a race condition in AESNI detection if certain compiler… CVSS 3.1HIGH 7.8
- TI-2025-30320 Use after free in mbedtls CVSS 3.1CRITICAL 9.8
- TI-2019-12830 Buffer overflows were discovered in the CoAP library in Arm Mbed OS 5.14.0. CVSS 3.1CRITICAL 9.8
- TI-2019-12829 An integer overflow was discovered in the CoAP library in Arm Mbed OS 5.14.0. CVSS 3.1CRITICAL 9.8
- TI-2025-31103 NULL pointer dereference in mbedtls CVSS 3.1HIGH 7.5
- TI-2025-31614 Out-of-bounds read in mbedtls CVSS 3.1MEDIUM 6.5
Sources
- CVE-2025-49087 · CVE Program
- CVE-2025-49087 · NVD
- FIRST EPSS
- GHSA-fmjv-q9m9-j657 · GitHub Advisory Database · CC BY 4.0
- CVE-2025-49087 · 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