🛡️ CVE-2026-34875 — mbed-tls

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• Attack vector: Network — reachable from anywhere that can route to the service.
• Attack complexity: Low — the attack works reliably, with no preparation.
• Privileges required: None — an unauthenticated stranger can try it.
• User interaction: None — nobody has to be tricked into anything.
• Scope: Unchanged — the damage stays inside the vulnerable component.
• Confidentiality impact: High — total loss, or loss the attacker controls.
• Integrity impact: High — total loss, or loss the attacker controls.
• Availability impact: High — total loss, or loss the attacker controls.

Weakness class

CVE-2026-34875 is classified as CWE-120: Classic Buffer Overflow. Input is copied into a fixed-size buffer without a length check, overwriting memory past the end of it.

Affected software

CVE-2026-34875 is recorded against 2 packages.

• mbed-tls (from 3.5.0 up to 3.6.6)
• tf-psa-crypto (fixed in 1.1.0)

Timeline and source

Published on 1 April 2026 and last revised on 17 June 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

mbed-tls.readthedocs.io
mbed-tls.readthedocs.io

Other advisories for this package

mbed-tls has other advisories on record. If you are patching this one, these are worth checking on the same host:

• CVE-2026-34877 (9.8 Critical, published 2 Apr 2026)
• CVE-2026-34876 (7.5 High, published 2 Apr 2026)
• CVE-2026-25835 (7.7 High, published 1 Apr 2026)
• CVE-2026-25834 (6.5 Medium, published 1 Apr 2026)
• CVE-2026-25833 (7.5 High, published 1 Apr 2026)
• CVE-2026-34874 (7.5 High, published 1 Apr 2026)
• CVE-2025-66442 (5.1 Medium, published 1 Apr 2026)
• CVE-2026-34873 (9.1 Critical, published 1 Apr 2026)

Same weakness in other software

These advisories are the same class of weakness (CWE-120: Classic Buffer Overflow) in other software:

• CVE-2019-5064 (8.0 High, published 9 Jul 2026)
• CVE-2022-29210 (5.0 Medium, published 6 Jul 2026)
• CVE-2021-41499 (8.0 High, published 2 Jul 2026)
• CVE-2022-29974 (4.3 Medium, published 9 Dec 2024)
• CVE-2022-20846 (4.3 Medium, published 15 Nov 2024)
• CVE-2022-32504 (9.8 Critical, published 14 May 2024)
• CVE-2022-24805 (6.5 Medium, published 16 Apr 2024)
• CVE-2022-24807 (6.5 Medium, published 16 Apr 2024)

CVE-2026-34875 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Affected Packages

References