CVE-2021-35331

Name: CVE-2021-35331
Creator: NVD / NIST
Published: 2021-07-05T15:15:07.997+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 1.64%

Last modified Jun 17, 2026

CVE-2021-35331 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. In Tcl 8.6.11, a format string vulnerability in nmakehlp.c might allow code execution via a crafted file. NOTE: multiple third parties dispute the significance of this finding. EPSS estimates a 1.64% chance of exploitation in the next 30 days.

Description

In Tcl 8.6.11, a format string vulnerability in nmakehlp.c might allow code execution via a crafted file. NOTE: multiple third parties dispute the significance of this finding

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

1.64%

73.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-134

Affected Software

Vendor	Product	Versions
Tcl	Tcl	8.6.11

References

https://core.tcl-lang.org/tcl/info/28ef6c0c741408a2Exploit, Patch, Vendor Advisory
https://core.tcl-lang.org/tcl/info/bad6cc213dfe8280Exploit, Vendor Advisory
https://github.com/tcltk/tcl/commit/4705dbdde2f32ff90420765cd93e7ac71d81a222Patch, Third Party Advisory
https://sqlite.org/forum/info/7dcd751996c93ec9Exploit, Third Party Advisory
https://core.tcl-lang.org/tcl/info/28ef6c0c741408a2Exploit, Patch, Vendor Advisory
https://core.tcl-lang.org/tcl/info/bad6cc213dfe8280Exploit, Vendor Advisory
https://github.com/tcltk/tcl/commit/4705dbdde2f32ff90420765cd93e7ac71d81a222Patch, Third Party Advisory
https://sqlite.org/forum/info/7dcd751996c93ec9Exploit, Third Party Advisory

Timeline

Published: Jul 5, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-35331?

In Tcl 8.6.11, a format string vulnerability in nmakehlp.c might allow code execution via a crafted file. NOTE: multiple third parties dispute the significance of this finding

How severe is CVE-2021-35331?

CVE-2021-35331 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 1.64% probability of exploitation in the next 30 days.

How do I fix CVE-2021-35331?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-35331?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST