How severe is CVE-2025-59438?

CVE-2025-59438 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2025-59438 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-59438?

CVE-2025-59438 affects Arm Mbed Tls. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-59438?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-59438 have an EU (EUVD) identifier?

Yes. CVE-2025-59438 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-35171.

When was CVE-2025-59438 published?

CVE-2025-59438 was published on 2025-10-21 and last updated on 2026-06-17.

CVE-2025-59438

CVE-2025-59438 is a medium-severity vulnerability in Arm Mbed Tls with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-208.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (15th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-35171
Weakness: CWE-208
Affected product: Arm Mbed Tls
Published: 2025-10-21
Last modified: 2026-06-17

Description

Mbed TLS through 3.6.4 has an Observable Timing Discrepancy.

Frequently asked questions

What is CVE-2025-59438?: Mbed TLS through 3.6.4 has an Observable Timing Discrepancy.
How severe is CVE-2025-59438?: CVE-2025-59438 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2025-59438 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-59438?: CVE-2025-59438 affects Arm Mbed Tls. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-59438?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-59438 have an EU (EUVD) identifier?: Yes. CVE-2025-59438 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-35171.
When was CVE-2025-59438 published?: CVE-2025-59438 was published on 2025-10-21 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:arm:mbed_tls:*:*:*:*:*:*:*:*

More vulnerabilities in Arm Mbed Tls

CVE-2026-34877 — Critical (CVSS 9.8): An issue was discovered in Mbed TLS versions from 2.19.0 up to 3.6.5, Mbed TLS 4.0.0. Insufficient protection of…
CVE-2022-46393 — Critical (CVSS 9.8): An issue was discovered in Mbed TLS before 2.28.2 and 3.x before 3.3.0. There is a potential heap-based buffer overflow…
CVE-2021-44732 — Critical (CVSS 9.8): Mbed TLS before 3.0.1 has a double free in certain out-of-memory conditions, as demonstrated by an…
CVE-2017-18187 — Critical (CVSS 9.8): In ARM mbed TLS before 2.7.0, there is a bounds-check bypass through an integer overflow in PSK identity parsing in the…
CVE-2018-0488 — Critical (CVSS 9.8): ARM mbed TLS before 1.3.22, before 2.1.10, and before 2.7.0, when the truncated HMAC extension and CBC are used, allows…
CVE-2018-0487 — Critical (CVSS 9.8): ARM mbed TLS before 1.3.22, before 2.1.10, and before 2.7.0 allows remote attackers to execute arbitrary code or cause…

All CVEs affecting Arm Mbed Tls →

Other CWE-208 vulnerabilities

CVE-2023-41313 — Critical (CVSS 9.8): The authentication method in Apache Doris versions before 2.0.0 was vulnerable to timing attacks. Users are recommended…
CVE-2024-42512 — High (CVSS 8.6): Vulnerability in the OPC UA .NET Standard Stack before 1.5.374.158 allows an unauthorized attacker to bypass…
CVE-2025-53940 — High (CVSS 8.5): Quiet is an alternative to team chat apps like Slack, Discord, and Element that does not require trusting a central…
CVE-2026-47784 — High (CVSS 8.1): In memcached before 1.6.42, password data for SASL password database authentication has a timing side channel because…
CVE-2026-47783 — High (CVSS 8.1): In memcached before 1.6.42, username data for SASL password database authentication has a timing side channel because a…
CVE-2026-42602 — High (CVSS 8.1): azureauthextension is the Azure Authenticator Extension. From 0.124.0 to 0.150.0, a server-side authentication bypass…

Browse all CWE-208 vulnerabilities →