CVE-2021-22144

In Elasticsearch versions before 7.13.3 and 6.8.17 an uncontrolled recursion vulnerability that could lead to a denial of service attack was identified in the Elasticsearch Grok parser. A user with the ability to submit arbitrary queries to Elasticsearch could create a malicious Grok query that will crash the Elasticsearch node.

Published: 2021-07-26 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-22144 is rated Moderate Risk (54.6/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.18%). Review affected assets and schedule remediation.

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-2021-22144

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 2026-07-13 1.66% 2.18% +0.52%
2 2026-06-15 0.47% 1.66% +1.19%
3 2026-06-09 — 0.47% —

Full EPSS history (18 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-22144

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H 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:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 [email protected]
4.0 2.0 MEDIUM
AV:N/AC:L/Au:S/C:N/I:N/A:P 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:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.0 2.9 [email protected]

Weakness enumeration for CVE-2021-22144

GitHub Security Advisory for CVE-2021-22144

GHSA-3393-hvrj-w7v3 · Severity: medium · Ecosystem: maven — Denial of Service in Elasticsearch

OS Trackers for CVE-2021-22144

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2021-22144
ubuntu medium CVE-2021-22144 medium priority: Ubuntu including 1 source packages (elasticsearch), 9 status rows across 9 suites (focal, jammy, mantic, noble, oracular, plucky, questing, upstream, xenial): DNE 7, needs-triage 2. https://ubuntu.com/security/CVE-2021-22144

Affected software / configurations for CVE-2021-22144

Vendor Product Version Raw CPE
elastic elasticsearch < 6.8.17 cpe:2.3:a:elastic:elasticsearch:*:*:*:*:*:*:*:*
elastic elasticsearch >= 7.0.0, < 7.13.3 cpe:2.3:a:elastic:elasticsearch:*:*:*:*:*:*:*:*
oracle communications_cloud_native_core_automated_test_suite 1.8.0 cpe:2.3:a:oracle:communications_cloud_native_core_automated_test_suite:1.8.0:*:*:*:*:*:*:*

References for CVE-2021-22144

cvelogic Threat Intelligence