Zed Attack Proxy (ZAP) ViewState add-on before version 4 contains an insecure deserialization vulnerability that allows attackers who control a proxied web server to achieve arbitrary code execution by embedding a malicious serialized Java object in the javax.faces.ViewState HTTP response parameter. The JSFViewState.decode() method base64-decodes the ViewState value and passes it directly to ObjectInputStream.readObject() without a deserialization filter, allowlist, or type restriction, causing the malicious object to be deserialized within the ZAP JVM when the Desktop UI renders the ViewState panel.
CVE-2026-57527
Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-06-26. a secondary CVSS source baseline 8.8; sources differ by 0.0.
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.8
- EG Score
- 8.8(medium)
- EG Risk
- 40(Track)EG Risk 40/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity88% × 45%Exploitation1% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 1%
- EPSS %ILE
- 50%
- KEV
- Not listed
Published
June 26, 2026
Last Modified
July 14, 2026
Advisory Details (5)
Auto-updated Jun 26, 2026ZAP – Java Deserialization Vulnerability in ZAP Viewstate Add-on
https://www.zaproxy.org/blog/2026-06-24-java-deserialization-vulnerability-in-zap-viewstate-addon/ZAP ViewState Add-on Insecure Deserialization via JSFViewState.decode() | Advisories | VulnCheck
https://www.vulncheck.com/advisories/zap-viewstate-add-on-insecure-deserialization-via-jsfviewstate-decodeViewState version 4
Patch available: zaproxy/zap-extensions viewstate-v4
https://github.com/zaproxy/zap-extensions/releases/tag/viewstate-v4viewstate: disable format
Patch available: zaproxy/zap-extensions viewstate-v4 (PR #7481 merged 2026-06-24)
https://github.com/zaproxy/zap-extensions/pull/7481commit ac6c3f94d385 (zaproxy/zap-extensions)
Patch available: zaproxy/zap-extensions viewstate-v4 (contains commit ac6c3f94d385)
https://github.com/zaproxy/zap-extensions/commit/ac6c3f94d38505bc0facea286a4d3728044c6e5cVendor Advisories for CVE-2026-57527(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 17× in last 7d / 103× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 209 total refreshes for this CVE.
- 2026-08-28 21:42 UTCEPSS rescore
- 2026-08-27 23:10 UTCEG score recompute
- 2026-08-27 23:10 UTCGHSA enrichment
- 2026-08-27 14:25 UTCEPSS rescore
- 2026-08-26 14:46 UTCEPSS rescore
- 2026-08-25 13:49 UTCEPSS rescore
- 2026-08-25 00:44 UTCEG score recompute
- 2026-08-25 00:44 UTCGHSA enrichment
- 2026-08-24 12:56 UTCEG score recompute
- 2026-08-24 12:56 UTCGHSA enrichment
- 2026-08-23 21:28 UTCGHSA enrichment
- 2026-08-23 09:41 UTCEG score recompute
- 2026-08-23 09:41 UTCGHSA enrichment
- 2026-08-23 00:19 UTCEPSS rescore
- 2026-08-22 21:54 UTCGHSA enrichment
- 2026-08-22 09:36 UTCEG score recompute
- 2026-08-22 09:36 UTCGHSA enrichment
- 2026-08-21 23:49 UTCEPSS rescore
- 2026-08-21 18:17 UTCGHSA enrichment
- 2026-08-21 06:29 UTCEG score recompute
- 2026-08-21 06:29 UTCGHSA enrichment
- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-20 18:41 UTCGHSA enrichment
- 2026-08-20 06:54 UTCEG score recompute
- 2026-08-20 06:54 UTCGHSA enrichment
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- 2026-08-19 17:04 UTCEPSS rescore
- 2026-08-19 12:38 UTCGHSA enrichment
- 2026-08-19 00:18 UTCEG score recompute
- 2026-08-19 00:18 UTCGHSA enrichment
- 2026-08-18 13:48 UTCEPSS rescore
- 2026-08-17 13:47 UTCEPSS rescore
- 2026-08-17 12:27 UTCGHSA enrichment
- 2026-08-17 00:17 UTCEG score recompute
- 2026-08-17 00:17 UTCGHSA enrichment
- 2026-08-16 14:56 UTCEPSS rescore
- 2026-08-16 12:30 UTCEG score recompute
- 2026-08-16 12:30 UTCGHSA enrichment
- 2026-08-16 02:14 UTCEPSS rescore
- 2026-08-16 00:43 UTCGHSA enrichment
- 2026-08-15 12:55 UTCEG score recompute
- 2026-08-15 12:55 UTCGHSA enrichment
- 2026-08-15 01:30 UTCEPSS rescore
- 2026-08-15 01:08 UTCGHSA enrichment
- 2026-08-14 13:21 UTCGHSA enrichment
- 2026-08-14 01:33 UTCEG score recompute
- 2026-08-14 01:33 UTCGHSA enrichment
- 2026-08-13 22:00 UTCEPSS rescore
- 2026-08-13 13:45 UTCGHSA enrichment
- 2026-08-13 01:52 UTCGHSA enrichment
- 2026-08-12 14:05 UTCEG score recompute
- 2026-08-12 14:05 UTCGHSA enrichment
- 2026-08-12 13:51 UTCEPSS rescore
- 2026-08-12 02:15 UTCGHSA enrichment
- 2026-08-11 14:27 UTCEG score recompute
- 2026-08-11 14:27 UTCGHSA enrichment
- 2026-08-11 02:38 UTCEG score recompute
- 2026-08-11 02:38 UTCGHSA enrichment
- 2026-08-11 00:00 UTCEPSS rescore
- 2026-08-10 14:51 UTCGHSA enrichment
- 2026-08-10 03:03 UTCGHSA enrichment
- 2026-08-09 15:16 UTCEG score recompute
- 2026-08-09 15:16 UTCGHSA enrichment
- 2026-08-09 13:46 UTCEPSS rescore
- 2026-08-09 03:29 UTCEG score recompute
- 2026-08-09 03:29 UTCGHSA enrichment
- 2026-08-08 16:37 UTCEPSS rescore
- 2026-08-08 15:42 UTCGHSA enrichment
- 2026-08-08 03:55 UTCEG score recompute
- 2026-08-08 03:55 UTCGHSA enrichment
- 2026-08-07 16:07 UTCGHSA enrichment
- 2026-08-07 04:19 UTCGHSA enrichment
- 2026-08-06 16:30 UTCEG score recompute
- 2026-08-06 16:30 UTCGHSA enrichment
- 2026-08-06 13:47 UTCEPSS rescore
- 2026-08-06 04:42 UTCEG score recompute
- 2026-08-06 04:42 UTCGHSA enrichment
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-05 16:55 UTCGHSA enrichment
- 2026-08-05 02:45 UTCEG score recompute
- 2026-08-05 02:45 UTCGHSA enrichment
- 2026-08-04 15:10 UTCEPSS rescore
- 2026-08-04 14:58 UTCEG score recompute
- 2026-08-04 14:58 UTCGHSA enrichment
- 2026-08-04 10:39 UTCEPSS rescore
- 2026-08-04 01:44 UTCGHSA enrichment
- 2026-08-03 13:57 UTCEG score recompute
- 2026-08-03 13:57 UTCGHSA enrichment
- 2026-08-03 10:36 UTCEPSS rescore
- 2026-08-03 01:20 UTCGHSA enrichment
- 2026-08-02 13:32 UTCEG score recompute
- 2026-08-02 13:32 UTCGHSA enrichment
- 2026-08-02 02:27 UTCEPSS rescore
- 2026-08-02 01:45 UTCGHSA enrichment
- 2026-08-01 13:57 UTCEG score recompute
- 2026-08-01 13:57 UTCGHSA enrichment
- 2026-08-01 04:16 UTCEPSS rescore
- 2026-08-01 02:09 UTCGHSA enrichment
- 2026-07-31 13:00 UTCGHSA enrichment
- 2026-07-31 01:12 UTCEG score recompute
- 2026-07-31 01:12 UTCGHSA enrichment
Related CVEs(same CWE)
Same CWE
10 shownCWE-502
- CVE-2017-10992EG 9.8EPSS p95CRITICAL
- CVE-2013-4521EG 9.8EPSS p90CRITICAL
- CVE-2014-1860EG 9.8CRITICAL
- CVE-2016-1000027EG 9.8EPSS p98CRITICAL
- CVE-2014-3699EG 9.8CRITICAL
- CVE-2017-10934EG 9.8CRITICAL
- CVE-2016-9498EG 9.8EPSS p97CRITICAL
- CVE-2016-9483EG 9.8CRITICAL
- CVE-2015-2020EG 9.8CRITICAL
- CVE-2017-15692EG 9.8EPSS p91CRITICAL
Frequently asked(5)
What is CVE-2026-57527?
When was CVE-2026-57527 disclosed?
Is CVE-2026-57527 actively exploited?
What is the CVSS score of CVE-2026-57527?
How do I remediate CVE-2026-57527?
Dependency Blast Radius
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