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No exploitation reported

CVE-2025-40909

No exploitation reported by the sources we read.

  • Published2025-05-30

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

Perl threads have a working directory race condition where file operations may target unintended paths. If a directory handle is open at thread creation, the process-wide current working directory is temporarily changed in order to clone that handle for the new thread, which is visible from any third (or more) thread already running. This may lead to unintended operations such as loading code or accessing files from unexpected locations, which a local attacker may be able to exploit. The bug was introduced in commit 11a11ecf4bea72b17d250cfb43c897be1341861e and released in Perl version 5.13.6

Timeline

dates in UTC
  1. 2025-05-3013:15CVE 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+4162+0aac7c4cand 5 other packages
  • perl-Algorithm-DiffAlmaLinux:8all versions · fixed in 1.1903-10.module_el8.6.0+2766+8bf0b7ce
  • perl-Archive-TarAlmaLinux:8all versions · fixed in 2.38-3.module_el8.6.0+2766+8bf0b7ce
  • 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
  • perl-AutoSplitAlmaLinux:8all versions · fixed in 5.74-474.module_el8.10.0+4162+0aac7c4cand 1 other package
  • perl-autouseAlmaLinux:8all versions · fixed in 1.11-474.module_el8.10.0+4162+0aac7c4cand 1 other package

174 more package ranges on OSV.dev

Vendor advisories

  • CVE-2025-40909 Red Hat Product Security2,559 products fixed · 68 known affected

    perl: Perl threads have a working directory race condition where file operations may target unintended paths

    perl as a component of Red Hat Enterprise Linux 6 · perl-Archive-Extract as a component of Red Hat Enterprise Linux 6 · perl-Archive-Tar as a component of Red Hat Enterprise Linux 6 · +65 more

  • RHSA-2026:50262 Red Hat Product Security11 products fixed

    Red Hat Security Advisory: perl:5.32 security update

  • RHSA-2026:37070 Red Hat Product Security820 products fixed

    Red Hat Security Advisory: perl:5.32 security update

  • RHSA-2026:8096 Red Hat Product Security794 products fixed

    Red Hat Security Advisory: perl:5.32 security update

  • RHSA-2025:13267 Red Hat Product Security2 products fixed

    Red Hat Security Advisory: A Subscription Management tool for finding and reporting Red Hat product usage

  • RHSA-2025:12056 Red Hat Product Security253 products fixed

    Red Hat Security Advisory: perl security update

3 more advisories

Full record on NVD

Fix

  1. Vendor fix Red Hat Product Security RHSA-2026:50262 · 11 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. Vendor fix Red Hat Product Security RHSA-2025:13267 · 2 productsThe containers required to run Discovery can be installed through discovery-installer RPM. See the official documentation for more details.
  3. Workaround from the vendor Red Hat Product Security RHSA-2026:50262 · 948 productsMitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
  4. No fix planned, says the vendor Red Hat Product Security CVE-2025-40909 · 66 productsOut of support scope

Detection

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

Sources

  • NVDCVE record2026-04-18
  • FIRST EPSSEPSS score0.5 %2026-10-22
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Published
2025-05-30
Last Modified
2026-04-18

Frequently asked questions

What is CVE-2025-40909?

Perl threads have a working directory race condition where file operations may target unintended paths. If a directory handle is open at thread creation, the process-wide current working directory is temporarily changed in order to clone that handle for the new thread, which is visible from any third (or more) thread already running. This may lead to unintended operations such as loading code or accessing files from unexpected locations, which a local attacker may be able to exploit. The bug was introduced in commit 11a11ecf4bea72b17d250cfb43c897be1341861e and released in Perl version 5.13.6

Is CVE-2025-40909 actively exploited?

Active exploitation of CVE-2025-40909 has not been confirmed. Its EPSS score was 0.5% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2025-40909?

CVE-2025-40909 has a CVSS v3 base score of 5.9 (MEDIUM severity), with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.

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