CVE-2026-39245
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Description
A flaw was found in the decompress component. An improper path containment check allows a local attacker to perform directory traversal. This vulnerability, when combined with unvalidated symlink creation, enables an attacker to write arbitrary files to directories outside the intended extraction target. This issue bypasses a previous fix for CVE-2020-12265.
Statement
Red Hat's assessment aligns with the CVSSv3.1 base score of 6.2 (Moderate) published by CVE.org/CISA for this issue. The vulnerable safeMakeDir/indexOf path-containment check described in this CVE exists only in decompress 4.2.1, the final release that addressed the earlier CVE-2020-12265 path traversal issue. The decompress npm package is no longer maintained upstream and no 4.2.2 release was ever published, despite the CVE description referring to a fix in that version. Some Red Hat products bundle much older decompress releases (0.2.5, 3.0.0) that predate this code path entirely and are not affected by this specific issue.
Mitigation
No upstream fix is available. The decompress package is unmaintained and no 4.2.2 release was ever published. Applications should avoid extracting untrusted archives with decompress 4.2.1, or migrate to a maintained fork such as @xhmikosr/decompress.
Additional information
- This content is not included.Bugzilla 2498814: decompress: decompress: path traversal via indexOf containment bypass allows arbitrary file write (bypass of CVE-2020-12265 fix)
- Content from cwe.mitre.org is not included.CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
External References
Content from www.cve.org is not included.https://www.cve.org/CVERecord?id=CVE-2026-39245
Content from nvd.nist.gov is not included.https://nvd.nist.gov/vuln/detail/CVE-2026-39245
Content from github.com is not included.https://github.com/kevva/decompress
Content from github.com is not included.https://github.com/kevva/decompress/issues/115
Content from nvd.nist.gov is not included.https://nvd.nist.gov/vuln/detail/CVE-2020-12265
Content from www.npmjs.com is not included.https://www.npmjs.com/package/decompress
Affected Packages and Issued Red Hat Security Errata
Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.
| Products / Services | Components | State | Errata |
|---|---|---|---|
| Red Hat Advanced Cluster Management for Kubernetes 2 | rhacm2/volsync-operator-bundle | Not affected | |
| Red Hat Advanced Cluster Management for Kubernetes 2 | rhacm2/volsync-rhel9 | Not affected | |
| Red Hat Build of Keycloak | decompress | Fix deferred | |
| Red Hat Hardened Images | dotnet8-0-main | Fixed | RHSA-2026:37577 |
Common Vulnerability Scoring System (CVSS) Score Details
Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authorities (CNA) source for its products and services (see Red Hat classifications ).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| CVSS v3 Base Score | 6.2 | N/A | 6.2 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality Impact | None | N/A | None |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
CVSS v3 Vector
Red Hat CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
cve.org CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Red Hat CVSS v3 Score Explanation
Mirrors CISA/CVE.org vector; local attack vector via crafted archive passed to decompress(), high integrity impact via arbitrary file write, no reason to diverge from third-party scoring.
Frequently Asked Questions
Why is Red Hat's CVSS v3 score or Impact different from other vendors?
For more information, see https://access.redhat.com/solutions/762393.
My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
- "Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.
- "Affected" means that our Analysis Team has determined that this product is affected by this vulnerability and might release a fix to address this in the near future.
What can I do if my product is listed as "Will not fix"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Upgrade to a supported product version that includes a fix for this vulnerability (recommended).
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
What can I do if my product is listed as "Fix deferred"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
- Red Hat Engineering focuses on addressing high-priority issues based on their complexity or limited lifecycle support. Therefore, lower-priority issues will not receive immediate fixes.
What is a mitigation?
I have a Red Hat product but it is not in the above list, is it affected?
Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?
My product is listed as "Out of Support Scope". What does this mean?
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