CVE-2021-29059: A vulnerability was discovered in IS-SVG version 2.1.0 to 4.2.2 and below where a Regular Expression Denial of

Q: How do I fix CVE-2021-29059?

is-svg: upgrade to 4.3.0. Exact commands for each OS are on this page.

Q: Is CVE-2021-29059 being exploited?

CVE-2021-29059 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-29059 affect?

CVE-2021-29059 affects is-svg. Severity is high (CVSS 7.5). A vulnerability was discovered in IS-SVG version 2.1.0 to 4.2.2 and below where a Regular Expression Denial of Service (ReDOS) occurs if the application is provided and checks a crafted invalid SVG string.

Q: How urgent is CVE-2021-29059?

Priority 58/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 7.5REMOTEUPGRADE

CVE-2021-29059 is a high-severity flaw (CVSS 7.5) affecting is-svg. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability was discovered in IS-SVG version 2.1.0 to 4.2.2 and below where a Regular Expression Denial of Service (ReDOS) occurs if the application is provided and checks a crafted invalid SVG string.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.6% (top 14%)
CISA exploited list	No
Weakness	CWE-770
Published	2021-06-21
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: is-svg project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-06-21 16:15 UTCPublished CVE record published
2026-06-17 03:47 UTCUpdated Record last modified

is-svg project is-svg UPGRADE

Affected: >= 2.1.0 and < 4.3.0

Fixed in: 4.3.0

Safe to downgrade to: a release before 2.1.0

1. Check installed version

npm ls is-svg

2. UPGRADE to 4.3.0

npm install is-svg@">=4.3.0"

3. If no update is available yet, DOWNGRADE to a release before 2.1.0

npm view is-svg versions npm install is-svg@"<2.1.0"

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-29059?

is-svg: upgrade to 4.3.0. Exact commands for each OS are on this page.

Is CVE-2021-29059 being exploited?

CVE-2021-29059 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-29059 affect?

CVE-2021-29059 affects is-svg. Severity is high (CVSS 7.5). A vulnerability was discovered in IS-SVG version 2.1.0 to 4.2.2 and below where a Regular Expression Denial of Service (ReDOS) occurs if the application is provided and checks a crafted invalid SVG string.

How urgent is CVE-2021-29059?

Priority 58/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2021-28092 HIGH 7.5 UPGRADE The is-svg package 2.1.0 through 4.2.1 for Node.js uses a regular expression that is vulnerable to Regular Exp

References

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