How severe is CVE-2026-18948?

CVE-2026-18948 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-18948 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-18948?

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.

When was CVE-2026-18948 published?

CVE-2026-18948 was published on 2026-08-10 and last updated on 2026-08-19.

CVE-2026-18948

CVE-2026-18948 is a critical-severity vulnerability with a CVSS 3.x base score of 9.9. 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-502.

Key facts

Severity: Critical (CVSS 3.x base score 9.9)
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-502
Published: 2026-08-10
Last modified: 2026-08-19

Description

A flaw was found in Feast. The system improperly deserializes user-defined functions (UDFs) stored in its registry, which are serialized using the 'dill' library. This allows a remote attacker to store a malicious UDF, leading to unauthenticated arbitrary code execution on the feature server in default configurations. An authenticated attacker can also achieve arbitrary code execution on the registry server by bypassing authorization checks during deserialization. This vulnerability can result in cross-tenant data access and lateral movement within the system.

Frequently asked questions

What is CVE-2026-18948?: A flaw was found in Feast. The system improperly deserializes user-defined functions (UDFs) stored in its registry, which are serialized using the 'dill' library. This allows a remote attacker to store a malicious UDF, leading to unauthenticated arbitrary code execution on the feature server in default configurations. An authenticated attacker can also achieve arbitrary code execution on the registry server by bypassing authorization checks during deserialization. This vulnerability can result in cross-tenant data access and lateral movement within the system.
How severe is CVE-2026-18948?: CVE-2026-18948 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-18948 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-18948?: 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.
When was CVE-2026-18948 published?: CVE-2026-18948 was published on 2026-08-10 and last updated on 2026-08-19.

References

Other CWE-502 (Deserialization of Untrusted Data) vulnerabilities

CVE-2026-69836 — Critical (CVSS 10.0): Deserialization of untrusted data in Microsoft Entra ID allows an unauthorized attacker to execute code over a network.
CVE-2026-17061 — Critical (CVSS 10.0): A Deserialization of Untrusted Data vulnerability affecting SIMULIA Execution Engine from Release 2023 through Release…
CVE-2026-11756 — Critical (CVSS 10.0): A Deserialization of Untrusted Data vulnerability affecting Station Launcher App in 3DEXPERIENCE platform from Release…
CVE-2026-41104 — Critical (CVSS 10.0): Deserialization of untrusted data in Microsoft Planetary Computer Pro allows an unauthorized attacker to disclose…
CVE-2026-43633 — Critical (CVSS 10.0): HestiaCP versions 1.9.0 through 1.9.4 contain a deserialization vulnerability in the web terminal component caused by a…
CVE-2026-33819 — Critical (CVSS 10.0): Deserialization of untrusted data in Microsoft Bing allows an unauthorized attacker to execute code over a network.

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