PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-59147 EGOR CVE debrief

The CVE-2026-59147 vulnerability affects the Data::DisjointSet::Shared Perl module, versions before 0.02. This vulnerability allows for out-of-bounds reads and writes due to an unvalidated parent index in the dsu_find function. The issue arises from the attach-time validator dsu_validate_header, which checks header scalars and region layout against the file size but does not validate the array contents. Consequently, when dsu_find walks and path-compresses parent[x] with x being a raw file-stored index not bounded against the node count, both the read and compression write-back operations occur out of bounds. A local peer that can write to the backing file can leave the header valid while poisoning the parent array. This can lead to the next find or union operations reading and writing through an out-of-bounds parent index, potentially corrupting memory or crashing the process.

Vendor
EGOR
Product
Data::DisjointSet::Shared
CVSS
Unknown
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-21
Original CVE updated
2026-07-22
Advisory published
2026-07-21
Advisory updated
2026-07-22

Who should care

Users of the Data::DisjointSet::Shared Perl module, version 0.02 or earlier, should be aware of this vulnerability. This includes developers and administrators who use or manage applications that utilize this module. Given the potential for memory corruption or process crashes, it is crucial for these users to update to a patched version of the module as soon as possible.

Technical summary

The Data::DisjointSet::Shared Perl module, versions before 0.02, is vulnerable to out-of-bounds reads and writes. This is due to the dsu_validate_header function not validating array contents after checking header scalars and region layout against the file size. The dsu_find function then uses an unvalidated parent index, leading to potential memory corruption or process crashes when a local peer can manipulate the backing file.

Defensive priority

High

Recommended defensive actions

  • Update to version 0.02 or later of the Data::DisjointSet::Shared Perl module.
  • Review and validate the integrity of files used by the module.
  • Implement additional monitoring for potential exploitation attempts.
  • Review compensating controls for exposed systems while remediation is scheduled and verified.
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review.
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented.
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The CVE record was published on 2026-07-21T20:17:03.513Z and was last modified on 2026-07-22T16:21:53.517Z. The NVD entry is currently Deferred. Evidence is limited to public sources and may not reflect the full scope or details of the vulnerability. Users should verify the integrity of affected systems and review vendor guidance for updates and mitigations. Defensive measures include monitoring for potential exploitation attempts and validating the integrity of files used by the module.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-21T20:17:03.513Z and has not been modified since then. The NVD entry is currently Deferred.