A Server-Side Template Injection was identified in Apache Syncope prior to 2.1.6 enabling attackers to inject arbitrary Java EL expressions, leading to an unauthenticated Remote Code Execution (RCE) vulnerability. Apache Syncope uses Java Bean Validation (JSR 380) custom constraint validators. When building custom constraint violation error messages, they support different types of interpolation, including Java EL expressions. Therefore, if an attacker can inject arbitrary data in the error message template being passed, they will be able to run arbitrary Java code.
CVE-2020-1959
This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 1.6%, top 18% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- 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
- 9.8
- EG Score
- 9.8(medium)
- EPSS
- 90.9%
- KEV
- Not listed
Published
May 4, 2020
Last Modified
November 21, 2024
Advisory Details (1)
Auto-updated Jul 7, 2026Affected Packages
(1 across 1 ecosystem)
Maven(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| org.apache.syncope:syncope-core | 1.0.0-RC1-incubating ... 2.1.5 (63 versions) | 2.1.6 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 11× in last 7d / 43× 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.
- 2026-07-11 08:25 UTCEPSS rescore
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- 2026-07-01 22:31 UTCOSV refresh
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- 2026-06-14 03:13 UTCOSV refresh
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- 2026-05-29 13:42 UTCEPSS rescore
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- 2026-05-27 13:39 UTCEPSS rescore
- 2026-05-27 03:59 UTCEG score recompute
- 2026-05-26 13:42 UTCEPSS rescore
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- 2026-05-24 16:48 UTCEPSS rescore
- 2026-05-24 11:51 UTCOSV refresh
Frequently asked(5)
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Dependency Blast Radius
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