CVE-2026-34871 — Use of Cryptographically Weak Pseudo-Random Number Generator in ARM Mbed TLS

CWE-338 — Use of Cryptographically Weak Pseudo-Random Number Generator9 documents7 sources
Severity
6.7MEDIUMNVD
EPSS
0.0%
top 97.35%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
ARM Mbed TLSARM Tf-psa-crypto
Timeline
PublishedApr 1
Latest updateApr 2

Description

An issue was discovered in Mbed TLS before 3.6.6 and 4.x before 4.1.0 and TF-PSA-Crypto before 1.1.0. There is a Predictable Seed in a Pseudo-Random Number Generator (PRNG).

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NExploitability: 1.4 | Impact: 5.2

Affected Packages2 packages

▶NVDarm/mbed_tls< 3.6.6
▶NVDarm/tf-psa-crypto< 1.1.0

🔴Vulnerability Details

4
OSV
CVE-2026-34871: (An issue was discovered in Mbed TLS before 3↗2026-04-02
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GHSA
GHSA-rjq9-c3rf-c638: An issue was discovered in Mbed TLS before 3↗2026-04-01
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CVEList
CVE-2026-34871: An issue was discovered in Mbed TLS before 3↗2026-04-01
▶
OSV
CVE-2026-34871: An issue was discovered in Mbed TLS before 3↗2026-04-01
▶

📋Vendor Advisories

1
Debian
CVE-2026-34871: mbedtls - An issue was discovered in Mbed TLS before 3.6.6 and 4.x before 4.1.0 and TF-PSA...↗2026
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🕵️Threat Intelligence

1
Wiz
CVE-2026-34871 Impact, Exploitability, and Mitigation Steps | Wiz↗
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💬Community

2
Bugzilla
CVE-2026-34871 micropython: entropy on Linux can fall back to /dev/urandom [fedora-all]↗2026-04-01
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Bugzilla
CVE-2026-34871 mbedtls: entropy on Linux can fall back to /dev/urandom [fedora-all]↗2026-04-01
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CVE-2026-34871 — ARM Mbed TLS vulnerability | cvebase