No exploitation reportedFix available

CVE-2021-26120

Q: Is CVE-2021-26120 actively exploited?

Active exploitation of CVE-2021-26120 has not been confirmed. Its EPSS score was 82.3% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-26120?

CVE-2021-26120 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.

Published2021-02-22
WeaknessCWE-94

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

Smarty before 3.1.39 allows code injection via an unexpected function name after a {function name= substring.

Timeline

dates in UTC

2021-02-2202:15CVE publishedNVD
2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 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-2021-26120?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-26120?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Debian debian linux

Branch	Affected	Fixed in	Source
9.0	= 9.0	no fix published	NVD
10.0	= 10.0	no fix published	NVD
11.0	= 11.0	no fix published	NVD

Smarty

Branch	Affected	Fixed in	Source
3.1	< 3.1.39	3.1.39	NVD

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

Fix

Advisories and patches

github.comRelease Notes
security.gentoo.orgPatch

Detection

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

Sources

NVDCVSS 3.19.8read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
NVDweakness (CWE)CWE-94read 2026-10-23
FIRST EPSSEPSS score82.3 %read 2026-10-23

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: 2021-02-22
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-26120?

Smarty before 3.1.39 allows code injection via an unexpected function name after a {function name= substring.

Is CVE-2021-26120 actively exploited?

Active exploitation of CVE-2021-26120 has not been confirmed. Its EPSS score was 82.3% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-26120?

CVE-2021-26120 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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