No exploitation reportedFix available

CVE-2020-36599

Q: Is CVE-2020-36599 actively exploited?

Active exploitation of CVE-2020-36599 has not been confirmed. Its EPSS score was 1.2% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2020-36599?

CVE-2020-36599 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.

No exploitation reported by the sources we read.

Published2022-08-18
Fixed in2.0.0 · 1.9.2
WeaknessCWE-116

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

lib/omniauth/failure_endpoint.rb in OmniAuth before 1.9.2 (and before 2.0) does not escape the message_key value.

Timeline

dates in UTC

2022-08-1823:15CVE 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-2020-36599?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-36599?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

OSV · NVD

Omniauth

Branch	Affected	Fixed in	Source
2.0	≥ 2.0.0.pre.rc1, < 2.0.0	2.0.0	OSV
1.9	< 1.9.2	1.9.2	NVD · OSV
2.0	= 2.0.0	no fix published	NVD

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

Fix

Update Omniauth to 2.0.0 · 1.9.2

Advisories and patches

github.comPatch

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.19.8read 2026-10-23
NVDweakness (CWE)CWE-116read 2026-10-23
FIRST EPSSEPSS score1.2 %2026-10-23
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: 2022-08-18
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2020-36599?

lib/omniauth/failure_endpoint.rb in OmniAuth before 1.9.2 (and before 2.0) does not escape the message_key value.

Is CVE-2020-36599 actively exploited?

Active exploitation of CVE-2020-36599 has not been confirmed. Its EPSS score was 1.2% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-36599?

CVE-2020-36599 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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