CVE-2026-59147

CVE-2026-59147 is a critical-severity vulnerability with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Description

Data::DisjointSet::Shared versions before 0.02 for Perl allow out-of-bounds reads and writes via an unvalidated parent index in dsu_find. The attach-time validator dsu_validate_header checks the header scalars and region layout against the file size, but does not validate the array contents it then trusts. dsu_find walks and path-compresses parent[x] with x a raw file-stored index never bounded against the node count, so both the read and the compression write-back land out of bounds. A local peer that can write the backing file can leave the header valid while poisoning the parent array, so the next find or union both reads and writes through an out-of-bounds parent index, corrupting memory or crashing the process.

Frequently asked questions

What is CVE-2026-59147?
Data::DisjointSet::Shared versions before 0.02 for Perl allow out-of-bounds reads and writes via an unvalidated parent index in dsu_find. The attach-time validator dsu_validate_header checks the header scalars and region layout against the file size, but does not validate the array contents it then trusts. dsu_find walks and path-compresses parent[x] with x a raw file-stored index never bounded against the node count, so both the read and the compression write-back land out of bounds. A local peer that can write the backing file can leave the header valid while poisoning the parent array, so the next find or union both reads and writes through an out-of-bounds parent index, corrupting memory or crashing the process.
How severe is CVE-2026-59147?
CVE-2026-59147 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-59147 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-59147?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-59147 published?
CVE-2026-59147 was published on 2026-07-21 and last updated on 2026-07-23.

References

Other CWE-125 (Out-of-bounds Read) vulnerabilities

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