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No exploitation reported

CVE-2026-9538

No exploitation reported by the sources we read.

  • Published2026-05-26

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Archive::Tar versions before 3.10 for Perl allow memory exhaustion via attacker controlled entry size field in tar header. _read_tar() reads each entry's payload with $handle->read($$data, $block), where $block is derived from the entry's 12-byte size field in the tar header with no upper bound on that value. A crafted header declaring a multi-gigabyte size causes Perl to allocate a scalar of that size.

Timeline

dates in UTC
  1. 2026-05-2602:16CVE publishedNVD

Versions per branch

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • perlAlmaLinux:8all versions · fixed in 4:5.32.1-474.module_el8.10.0+4240+a58b978cand 2 other packages
  • perl-Algorithm-DiffAlmaLinux:8all versions · fixed in 1.1903-10.module_el8.6.0+2766+8bf0b7ce
  • perl-Archive-TarAlmaLinux:10all versions · fixed in 3.02-512.el10_2.2
  • perl-Archive-TarAlmaLinux:9all versions · fixed in 2.38-6.el9_8.2
  • perl-Archive-TarAlmaLinux:8all versions · fixed in 2.30-3.el8_10
  • perl-Archive-ZipAlmaLinux:8all versions · fixed in 1.68-3.module_el8.6.0+2766+8bf0b7ce
  • perl-Attribute-HandlersAlmaLinux:8all versions · fixed in 1.01-474.module_el8.10.0+4162+0aac7c4c
  • perl-autodieAlmaLinux:8all versions · fixed in 2.34-1.module_el8.6.0+2766+8bf0b7ce

185 more package ranges on OSV.dev

Vendor advisories

  • CVE-2026-9538 Red Hat Product Security800 products fixed · 2 known affected

    perl-Archive-Tar: perl-Archive-Tar: Denial of Service via crafted tar header with large entry size

    perl-Archive-Tar as a component of Red Hat Enterprise Linux 7 · perl-Archive-Tar.src as a component of Red Hat Enterprise Linux 7

  • RHSA-2026:49523 Red Hat Product Security2 products fixed

    Red Hat Security Advisory: perl-Archive-Tar security update

  • RHSA-2026:49525 Red Hat Product Security2 products fixed

    Red Hat Security Advisory: perl-Archive-Tar security update

  • RHSA-2026:49524 Red Hat Product Security2 products fixed

    Red Hat Security Advisory: perl-Archive-Tar security update

  • RHSA-2026:48225 Red Hat Product Security794 products fixed

    Red Hat Security Advisory: perl:5.32 security update

Full record on NVD

Fix

  1. Vendor fix Red Hat Product Security RHSA-2026:49523 · 2 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
  2. Workaround from the vendor Red Hat Product Security RHSA-2026:49523 · 2 productsTo mitigate this issue, avoid processing untrusted tar archives with applications using Perl's Archive::Tar module. If untrusted tar processing is required, consider imposing resource limits (e.g., ulimit) on the processes handling tar files to contain memory exhaustion and prevent wider system imp…
  3. No fix available, says the vendor Red Hat Product Security CVE-2026-9538 · 2 productsAffected

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Published
2026-05-26
Last Modified
2026-07-23
MSRC Title
Archive::Tar versions before 3.10 for Perl allow memory exhaustion via attacker controlled entry size field in tar header

Frequently asked questions

What is CVE-2026-9538?

Archive::Tar versions before 3.10 for Perl allow memory exhaustion via attacker controlled entry size field in tar header. _read_tar() reads each entry's payload with $handle->read($$data, $block), where $block is derived from the entry's 12-byte size field in the tar header with no upper bound on that value. A crafted header declaring a multi-gigabyte size causes Perl to allocate a scalar of that size.

Is CVE-2026-9538 actively exploited?

Active exploitation of CVE-2026-9538 has not been confirmed. Its EPSS score was 0.4% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-9538?

CVE-2026-9538 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

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