CVE-2020-27831

A flaw was found in Red Hat Quay, where it does not properly protect the authorization token when authorizing email addresses for repository email notifications. This flaw allows an attacker to add email addresses they do not own to repository notifications.

Published: 2021-05-26 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-27831 is rated Low Risk (32.1/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.55%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-27831

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.13% 0.55% +0.42%
2 2025-03-30 0.20% 0.13% -0.07%
3 2025-03-29 — 0.20% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-27831

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 1.4 [email protected]
4.0 2.0 MEDIUM
AV:N/AC:L/Au:S/C:N/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 8.0 2.9 [email protected]

Weakness enumeration for CVE-2020-27831

OS Trackers for CVE-2020-27831

vendor priority summary link
redhat low — https://access.redhat.com/security/cve/CVE-2020-27831

Affected software / configurations for CVE-2020-27831

Vendor Product Version Raw CPE
redhat quay >= 3.0.0, < 3.3.3 cpe:2.3:a:redhat:quay:*:*:*:*:*:*:*:*

References for CVE-2020-27831

URL Tags
https://bugzilla.redhat.com/show_bug.cgi?id=1905758 Issue Tracking Vendor Advisory
cvelogic Threat Intelligence