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TI-2026-27108 Aliases CVE-2026-34872GHSA-347r-37hj-5jc9

An issue was discovered in Mbed TLS 3.5.x and 3.6.x through 3.6.5 and TF-PSA-Crypto 1.0.

Priority MEDIUM 45CWE-347Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-347.

Summary

An issue was discovered in Mbed TLS 3.5.x and 3.6.x through 3.6.5 and TF-PSA-Crypto 1.0. There is a lack of contributory behavior in FFDH due to improper input validation. Using finite-field Diffie-Hellman, the other party can force the shared secret into a small set of values (lack of contributory behavior). This is a problem for protocols that depend on contributory behavior (which is not the case for TLS). The attack can be carried by the peer, or depending on the protocol by an active network attacker (person in the middle).

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00208 10th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:arm:mbed_tls:*:*:*:*:*:*:*:*before 3.6.6VulnerableArm
cpe:2.3:a:arm:tf-psa-crypto:1.0.0:-:*:*:*:*:*:*1.0.0VulnerableArm
  • cpe:2.3:a:arm:mbed_tls:*:*:*:*:*:*:*:* Versions before 3.6.6 Vulnerable ·Arm
  • cpe:2.3:a:arm:tf-psa-crypto:1.0.0:-:*:*:*:*:*:* Versions 1.0.0 Vulnerable ·Arm

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34872
  2. 2026-10-03 Alias added: GHSA-347r-37hj-5jc9

References

Advisory 2

  • TI-2023-28736 An issue was discovered in Mbed TLS through 3.5.1. CVSS 3.1HIGH 7.5
  • TI-2021-19505 A Denial of Service vulnerability exists in mbed TLS 3.0.0 and earlier in the… CVSS 3.1HIGH 7.5
  • 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-2022-22925 An issue was discovered in Mbed TLS before 2.28.2 and 3.x before 3.3.0. CVSS 3.1CRITICAL 9.8
  • TI-2018-00445 Out-of-bounds write in ARM mbed TLS before 1.3.22, before 2.1.10, and before 2.7.0 CVSS 3.0CRITICAL 9.8
  • TI-2026-27113 An issue was discovered in Mbed TLS versions from 2.19.0 up to 3.6.5, Mbed TLS 4.0.0. CVSS 3.1CRITICAL 9.8
See all 50 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences