CVE-2026-40931: Compressing is a compressing and uncompressing lib for node

Q: How do I fix CVE-2026-40931?

compressing: upgrade to 1.10.5, 2.1.1. Exact commands for each OS are on this page.

Q: Is CVE-2026-40931 being exploited?

CVE-2026-40931 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-2026-40931 affect?

CVE-2026-40931 affects compressing. Severity is high (CVSS 8.4). Compressing is a compressing and uncompressing lib for node. Prior to 2.1.1 and 1.10.5, the patch for CVE-2026-24884 relies on a purely logical string validation within the isPathWithinParent utility. This check verifies if a resolved path

Q: How urgent is CVE-2026-40931?

Priority 39/100. High severity; Public exploit reference

Routine

HIGH 8.4UPGRADE

CVE-2026-40931 is a high-severity flaw (CVSS 8.4) affecting compressing. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Compressing is a compressing and uncompressing lib for node. Prior to 2.1.1 and 1.10.5, the patch for CVE-2026-24884 relies on a purely logical string validation within the isPathWithinParent utility. This check verifies if a resolved path string starts with the destination directory string but fails to account for the actual filesystem state. By exploiting this "Logical vs. Physical" divergence, an attacker can bypass the security check using a

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	8.4 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 83%)
CISA exploited list	No
Weakness	CWE-59
Published	2026-04-21
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc. · Vendor: node-modules

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-21 22:16 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

node-modules compressing UPGRADE

Affected: < 1.10.5 · >= 2.0.0 and < 2.1.1

Fixed in: 1.10.5, 2.1.1

Safe to downgrade to: a release before 2.0.0

1. Check installed version

npm ls compressing

2. UPGRADE to 1.10.5

npm install compressing@">=1.10.5"

3. If no update is available yet, DOWNGRADE to a release before 2.0.0

npm view compressing versions npm install compressing@"<2.0.0"

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-2026-40931?

compressing: upgrade to 1.10.5, 2.1.1. Exact commands for each OS are on this page.

Is CVE-2026-40931 being exploited?

CVE-2026-40931 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-2026-40931 affect?

CVE-2026-40931 affects compressing. Severity is high (CVSS 8.4). Compressing is a compressing and uncompressing lib for node. Prior to 2.1.1 and 1.10.5, the patch for CVE-2026-24884 relies on a purely logical string validation within the isPathWithinParent utility. This check verifies if a resolved path

How urgent is CVE-2026-40931?

Priority 39/100. High severity; Public exploit reference

References

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