How severe is CVE-2025-34468?

CVE-2025-34468 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-34468 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-34468?

CVE-2025-34468 affects Libcoap. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-34468?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2025-34468 have an EU (EUVD) identifier?

Yes. CVE-2025-34468 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-206064.

When was CVE-2025-34468 published?

CVE-2025-34468 was published on 2025-12-31 and last updated on 2026-06-17.

CVE-2025-34468

CVE-2025-34468 is a critical-severity vulnerability in Libcoap with a CVSS 3.x base score of 9.8. 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-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 8.2
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-206064
Weakness: CWE-787
Affected product: Libcoap
Published: 2025-12-31
Last modified: 2026-06-17

Description

libcoap versions up to and including 4.3.5, prior to commit 30db3ea, contain a stack-based buffer overflow in address resolution when attacker-controlled hostname data is copied into a fixed 256-byte stack buffer without proper bounds checking. A remote attacker can trigger a crash and potentially achieve remote code execution depending on compiler options and runtime memory protections. Exploitation requires the proxy logic to be enabled (i.e., the proxy request handling code path in an application using libcoap).

Frequently asked questions

What is CVE-2025-34468?: libcoap versions up to and including 4.3.5, prior to commit 30db3ea, contain a stack-based buffer overflow in address resolution when attacker-controlled hostname data is copied into a fixed 256-byte stack buffer without proper bounds checking. A remote attacker can trigger a crash and potentially achieve remote code execution depending on compiler options and runtime memory protections. Exploitation requires the proxy logic to be enabled (i.e., the proxy request handling code path in an application using libcoap).
How severe is CVE-2025-34468?: CVE-2025-34468 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-34468 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-34468?: CVE-2025-34468 affects Libcoap. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-34468?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-34468 have an EU (EUVD) identifier?: Yes. CVE-2025-34468 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-206064.
When was CVE-2025-34468 published?: CVE-2025-34468 was published on 2025-12-31 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:libcoap:libcoap:*:*:*:*:*:*:*:*

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