Archive::Tar: Improper Link Resolution Before File Access
CVE-2026-42496 is a critical-severity improper link resolution before file access vulnerability in Archive::Tar from BINGOS, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 3.08 as the first without the flaw, so updating Archive::Tar to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.5% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Archive::Tar to 3.08 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| BINGOS | Archive::Tar | before 3.08 | 3.08 |
| Red Hat | Red Hat Enterprise Linux 10 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 7 | Not specified in the record | Not stated |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) | V3.1.7 and later | Not stated |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) | V3.1.7 and later | Not stated |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) | V3.1.7 and later | Not stated |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) | V3.1.7 and later | Not stated |
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) | V3.1.7 and later | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.1 | Critical | NVD |
| CVSS 3.1 | 9.1 | Critical | CISA (ADP) |
| CVSS 3.1 | 8.2 | High | CNA |
Official description
Archive::Tar versions before 3.08 for Perl extract symlinks with attacker controlled targets outside the extraction directory. _make_special_file() passes the tar header's linkname to symlink() without validating it against absolute paths or .. segments. The secure-extract mode check that guards regular file extraction does not cover the symlink target. A subsequent open through the extracted name reads or writes the attacker chosen path.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Link Resolution Before File Access
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
How developers prevent this class of flaw
- Follow the principle of least privilege when assigning access rights to entities in a software system. Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.
More Improper Link Resolution Before File Access vulnerabilities (CWE-59)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Third-party and government advisories
- cve.org/CVERecord?id=CVE-2026-42497Third Party Advisory
Other references
- access.redhat.com/errata/RHSA-2026:30851
- access.redhat.com/errata/RHSA-2026:30852
- access.redhat.com/errata/RHSA-2026:30856
- access.redhat.com/errata/RHSA-2026:30857
- access.redhat.com/security/cve/CVE-2026-42496
- bugzilla.redhat.com/show_bug.cgi?id=2481314
- cert-portal.siemens.com/productcert/html/ssa-457936.html
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42496.json
Other vulnerabilities in Archive::Tar
- 7.5 High severity
- 7.5 High severity
Recent Improper Link Resolution Before File Access vulnerabilities
- 9.9 Critical severity
- 7.8 High severity
- 8.1 High severity
- 7.8 High severity
Microsoft Defender Link Following Exploited
- 7.4 High severity
- 7.8 High severity
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