VulnerabilityPublished 26 May 2026Updated 6 Nov 2026

CVE-2026-42497: Archive::Tar versions before 3.08 for Perl extract hardlinks to attacker controlled paths outside the

Affects perlSource GCVE Database

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Authoritative record:CVE-2026-42497· High 7.5

Not known to be exploited · CVSS 7.5 High : upgrade to 5.38.2-3.2ubuntu0.3 soon.

Data as of 6 Nov 2026, 15:38 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 5.38.2-3.2ubuntu0.3

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 26 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade the Ubuntu perl package to 5.38.2-3.2ubuntu0.3.

Affected software

Product	Affected	Fixed in
Ubuntu 26.10perl`pkg:deb/ubuntu/perl?arch=source&distro=stonking`Other threats	Affected 5.40.1-7build1 – 5.42.3-1 4 affected builds	Fixed in–
Ubuntu 25.10perl`pkg:deb/ubuntu/perl?arch=source&distro=questing`Other threats	Affected 5.40.1-2 – 5.40.1-6ubuntu0.1 6 affected builds	Fixed in–
Ubuntu 24.04 LTSperl`pkg:deb/ubuntu/perl?arch=source&distro=noble`Other threats	Affected <5.38.2-3.2ubuntu0.3	Fixed in 5.38.2-3.2ubuntu0.3
Ubuntu 22.04 LTSperl`pkg:deb/ubuntu/perl?arch=source&distro=jammy`Other threats	Affected 5.32.1-3ubuntu3 – 5.34.0-3ubuntu1.9 10 affected builds	Fixed in–
Ubuntu Pro 20.04 LTSperl`pkg:deb/ubuntu/perl?arch=source&distro=esm-infra/focal`Other threats	Affected 5.28.1-6build1 – 5.30.0-9ubuntu0.5+esm4 11 affected builds	Fixed in–
Ubuntu Pro 18.04 LTSperl`pkg:deb/ubuntu/perl?arch=source&distro=esm-infra/bionic`Other threats	Affected 5.26.0-8ubuntu1 – 5.26.1-6ubuntu0.7+esm4 16 affected builds	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available in Archive::Tar version 3.08 and later. Users should upgrade to version 3.08 or apply the fixed version 5.38.2-3.2ubuntu0.3 or later in their distributions. Until patched, avoid extracting untrusted tar archives with vulnerable versions of Archive::Tar. No other vendor advisory states that the issue is already mitigated or requires no action.

Description

Archive::Tar versions before 3.08 for Perl contain a vulnerability where hardlinks in tar archives can be extracted to attacker-controlled paths outside the intended extraction directory. This occurs because the function handling special files does not validate the linkname against absolute paths or directory traversal sequences, allowing an attacker to create a hardlink that shares an inode with a victim file. Subsequent writes to the extracted file modify the victim file, and file metadata changes are applied to the shared inode during extraction.

Impact

An attacker can craft a malicious tar archive that, when extracted by vulnerable versions of Archive::Tar, creates hardlinks to files outside the extraction directory. This leads to unauthorized modification of arbitrary files on the victim system without requiring privileges. The vulnerability has a CVSS score of 7.5 (high severity) with network attack vector, low attack complexity, no privileges required, and no user interaction needed. The impact is integrity loss (I:H) without confidentiality or availability impact.

Summary

The vulnerability in Archive::Tar versions prior to 3.08 for Perl arises from improper validation of hardlink paths during extraction. The _make_special_file() function passes the tar header's linkname directly to the link() system call without checking for absolute paths or '..' segments. This allows an attacker to create a hardlink pointing outside the extraction directory, causing the extracted file and the victim file to share the same inode. Consequently, modifications to the extracted file affect the victim file. Additionally, the post-extraction operations that set file mode, ownership, and timestamps apply to the shared inode, potentially altering critical system files or other sensitive files.

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Affected software

Description

AI analysisMachine-generated, updated 6 Nov 2026, 15:38 UTC

Technical details

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