How severe is CVE-2026-3967?

CVE-2026-3967 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-3967 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.

How do I fix CVE-2026-3967?

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

Does CVE-2026-3967 have an EU (EUVD) identifier?

Yes. CVE-2026-3967 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-11492.

When was CVE-2026-3967 published?

CVE-2026-3967 was published on 2026-03-12 and last updated on 2026-06-17.

CVE-2026-3967

CVE-2026-3967 is a medium-severity vulnerability with a CVSS 3.x base score of 6.3. 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-20.

Key facts

Severity: Medium (CVSS 3.x base score 6.3)
CVSS v2: 6.5
CVSS v4: 2.1
EPSS exploit prediction: 0% (15th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-11492
Weakness: CWE-20
Published: 2026-03-12
Last modified: 2026-06-17

Description

A flaw has been found in Alfresco Activiti up to 7.19/8.8.0. Affected by this issue is the function deserialize/createObjectInputStream of the file activiti-core/activiti-engine/src/main/java/org/activiti/engine/impl/variable/SerializableType.java of the component Process Variable Serialization System. This manipulation causes deserialization. Remote exploitation of the attack is possible. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Frequently asked questions

What is CVE-2026-3967?: A flaw has been found in Alfresco Activiti up to 7.19/8.8.0. Affected by this issue is the function deserialize/createObjectInputStream of the file activiti-core/activiti-engine/src/main/java/org/activiti/engine/impl/variable/SerializableType.java of the component Process Variable Serialization System. This manipulation causes deserialization. Remote exploitation of the attack is possible. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
How severe is CVE-2026-3967?: CVE-2026-3967 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-3967 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.
How do I fix CVE-2026-3967?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-3967 have an EU (EUVD) identifier?: Yes. CVE-2026-3967 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-11492.
When was CVE-2026-3967 published?: CVE-2026-3967 was published on 2026-03-12 and last updated on 2026-06-17.

References

Other CWE-20 (Improper Input Validation) vulnerabilities

CVE-2026-48316 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48281 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48277 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48055 — Critical (CVSS 10.0): Streambert is a cross-platform Electron Desktop App to stream and download any video media. In versions 2.4.0 and…
CVE-2026-34910 — Critical (CVSS 10.0): A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi OS…
CVE-2026-33587 — Critical (CVSS 10.0): Lack of user input sanitisation in Open Notebook v1.8.3 allows the application user to execute Python code (and…

Browse all CWE-20 (Improper Input Validation) vulnerabilities →