CVE-2025-59438: arm mbed_tls Observable Timing Discrepancy
CVSS: 5.3v3.1MediumAnalyzed
AliasesALPINE-CVE-2025-59438SUSE-SU-2026:1413-1SUSE-SU-2026:20769-1SUSE-SU-2026:21018-1SUSE-SU-2026:21161-1UBUNTU-CVE-2025-59438DEBIAN-CVE-2025-59438openSUSE-SU-2025:15662-1openSUSE-SU-2025:20035-1openSUSE-SU-2026:10083-1openSUSE-SU-2026:10378-1openSUSE-SU-2026:20499-1
Published 21-10-2025Last modified 21-10-2025
Vulnerability summary
CVE-2025-59438 is a medium (CVSS 5.3) Observable Timing Discrepancy vulnerability in arm mbed_tls. EPSS estimates a 0.26% chance of exploitation in the next 30 days, higher than 17.1% of scored vulnerabilities.
CVSS score
5.3/10
010
Medium · v3.1 (CVE.org)EPSS score
0.26%
0%100%
Low · +0.02 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 4 · Related 4Timeline
- 21-10-2025PublishedVulnerability first disclosed.
- 21-10-2025Last modifiedVulnerability information updated.
Description
Mbed TLS through 3.6.4 has an Observable Timing Discrepancy.
CVSS metrics
5 scores · 5 sources · 1 versionMedium 5.3Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NSourcesAll 5 agree
- OSV · AlpineEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- OSV · UbuntuEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- OSV · DebianEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- NVDNIST5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS trend
Probability
0.26%
Chance of exploitation in the next 30 days
Percentile
17%
Versus all other CVEs
30-day change
+0.02 pp
From 0.25% on 19-09-2026
19-09-202619-10-2026
EPSS score0.26%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Suse6 products
- ovmf&distro=SUSE Linux Enterprise Module for Package Hub 15 SP7< 202408-150700.3.15.1
- ovmf&distro=SUSE Linux Enterprise Module for Server Applications 15 SP7< 202408-150700.3.15.1
- ovmf&distro=SUSE Linux Enterprise Server 16.0< 202502-160000.4.1
- ovmf&distro=SUSE Linux Enterprise Server for SAP applications 16.0< 202502-160000.4.1
- ovmf&distro=SUSE Linux Micro 6.1< 202402-slfo.1.1_2.1
Opensuse5 products
- micropython&distro=openSUSE Leap 16.0< 1.26.0-bp160.1.1
- micropython&distro=openSUSE Tumbleweed< 1.26.0-2.1
- ovmf&distro=openSUSE Leap 16.0< 202502-160000.4.1
- ovmf&distro=openSUSE Tumbleweed< 202602-5.1
- vlang&distro=openSUSE Tumbleweed< 0.5-2.1
Alpine1 product
- mbedtls< 3.6.5-r0
Arm1 product
- mbed_tls< 3.6.5
Debian1 product
- mbedtlsAll versions (No fix recorded) | < 3.6.5-0.1~deb13u1 | < 3.6.5-0.1
Ubuntu1 product
- mbedtlsAll versions (No fix recorded)
6 vendors · 15 products
