How severe is CVE-2020-17531?

CVE-2020-17531 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-17531 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 10% (95th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-17531?

CVE-2020-17531 affects Apache Tapestry. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-17531?

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-2020-17531 published?

CVE-2020-17531 was published on 2020-12-08 and last updated on 2026-06-17.

CVE-2020-17531

CVE-2020-17531 is a critical-severity vulnerability in Apache Tapestry with a CVSS 3.x base score of 9.8. 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 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 10% (95th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-502
Affected product: Apache Tapestry
Published: 2020-12-08
Last modified: 2026-06-17

Description

A Java Serialization vulnerability was found in Apache Tapestry 4. Apache Tapestry 4 will attempt to deserialize the "sp" parameter even before invoking the page's validate method, leading to deserialization without authentication. Apache Tapestry 4 reached end of life in 2008 and no update to address this issue will be released. Apache Tapestry 5 versions are not vulnerable to this issue. Users of Apache Tapestry 4 should upgrade to the latest Apache Tapestry 5 version.

Frequently asked questions

What is CVE-2020-17531?: A Java Serialization vulnerability was found in Apache Tapestry 4. Apache Tapestry 4 will attempt to deserialize the "sp" parameter even before invoking the page's validate method, leading to deserialization without authentication. Apache Tapestry 4 reached end of life in 2008 and no update to address this issue will be released. Apache Tapestry 5 versions are not vulnerable to this issue. Users of Apache Tapestry 4 should upgrade to the latest Apache Tapestry 5 version.
How severe is CVE-2020-17531?: CVE-2020-17531 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-17531 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 10% (95th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-17531?: CVE-2020-17531 affects Apache Tapestry. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-17531?: 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-2020-17531 published?: CVE-2020-17531 was published on 2020-12-08 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:apache:tapestry:*:*:*:*:*:*:*:*

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