CVE-2026-57527: zaproxy zap-extensions

ZAP ViewState Add-on Insecure Deserialization via JSFViewState.decode()

CVSS 8.7 HighEPSS 0.0068 · 52nd percentile

Published by the CVE Program (CNA: VulnCheck) at 26 Jun 2026, 14:43 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
zaproxy	zap-extensions pkg:github/zaproxy/zap-extensions	affected before 4 custom Other versions: affected

Identifiers

CVE-2026-57527

CNA

VulnCheck

Weakness (CWE)

CWE-502

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
8.7	High	4.0	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N	CNA (VulnCheck)Used for this record
8.8	High	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H	CNA (VulnCheck)

CISA KEV Not listed.
EPSS 0.0068, the 52nd percentile, on 10 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

26 Jun 2026, 14:43 UTC Confirmed by the CVE List

Sources

References from the CNA

www.zaproxy.org/blog/2026-06-24-java-deserialization-vulnerability-in-zap-viewstate-addon/ technical-descriptionvendor-advisory
github.com/zaproxy/zap-extensions/releases/tag/viewstate-v4 release-notes
github.com/zaproxy/zap-extensions/pull/7481 issue-trackingpatch
github.com/zaproxy/zap-extensions/commit/ac6c3f94d38505bc0facea286a4d3728044c6e5c patch
www.vulncheck.com/advisories/zap-viewstate-add-on-insecure-deserialization-via-jsfviewstate-decode third-party-advisory

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.