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No exploitation reportedFix available

CVE-2020-8159

No exploitation reported by the sources we read.

  • Published2020-05-12
  • WeaknessCWE-22

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

There is a vulnerability in actionpack_page-caching gem < v1.2.1 that allows an attacker to write arbitrary files to a web server, potentially resulting in remote code execution if the attacker can write unescaped ERB to a view.

Timeline

dates in UTC
  1. 2020-05-1213:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-8159?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-8159?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV
Debian debian linux
BranchAffectedFixed in
9.0= 9.0no fix published
Rubyonrails actionpack page-caching
BranchAffectedFixed in
1.2< 1.2.11.2.1

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

No fix published by the sources we read yet. NVD record

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • NVDCVSS 3.19.8read 2026-10-23
  • NVDCVSS 2.07.5read 2026-10-23
  • CNAweakness (CWE)CWE-22read 2026-10-23
  • NVDweakness (CWE)CWE-22read 2026-10-23
  • FIRST EPSSEPSS score5.4 %2026-10-22
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2020-05-12
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2020-8159?

There is a vulnerability in actionpack_page-caching gem < v1.2.1 that allows an attacker to write arbitrary files to a web server, potentially resulting in remote code execution if the attacker can write unescaped ERB to a view.

Is CVE-2020-8159 actively exploited?

Active exploitation of CVE-2020-8159 has not been confirmed. Its EPSS score was 5.4% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-8159?

CVE-2020-8159 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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