🛡️ CVE-2026-25833 — 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 none, integrity none, 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:N/I:N/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: None.
• Integrity impact: None.
• Availability impact: High — total loss, or loss the attacker controls.

Weakness class

CVE-2026-25833 is classified as CWE-121: Stack-based Buffer Overflow. An oversized write to a stack buffer overwrites saved state such as return addresses, which can redirect execution.

Affected software

CVE-2026-25833 is recorded against 1 package.

• mbed-tls

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-2026-34871 (6.7 Medium, published 1 Apr 2026)
• CVE-2026-25835 (7.7 High, published 1 Apr 2026)
• CVE-2026-25834 (6.5 Medium, published 1 Apr 2026)
• CVE-2026-34875 (9.8 Critical, published 1 Apr 2026)
• CVE-2025-66442 (5.1 Medium, published 1 Apr 2026)
• CVE-2026-34874 (7.5 High, published 1 Apr 2026)

Same weakness in other software

These advisories are the same class of weakness (CWE-121: Stack-based Buffer Overflow) in other software:

• CVE-2023-28760 (7.5 High, published 2 Oct 2025)
• CVE-2022-32502 (6.3 Medium, published 14 May 2024)
• CVE-2023-27333 (6.8 Medium, published 3 May 2024)
• CVE-2023-32146 (8.8 High, published 3 May 2024)
• CVE-2023-27332 (8.8 High, published 3 May 2024)
• CVE-2023-32144 (8.8 High, published 3 May 2024)
• CVE-2023-27369 (8.8 High, published 3 May 2024)
• CVE-2023-32142 (8.8 High, published 3 May 2024)

CVE-2026-25833 on other distributions

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

Details

Affected Packages

References