Data::SortedSet::Shared implements rank and min/max queries against a memory‑mapped backing file. It bounds only the root node index before traversing child pointers; the child node indices are read directly from the file without validating them against the pool size. An attacker who can alter the backing file may corrupt the tree links so that subsequent queries dereference an out‑of‑bounds index, causing a read of adjacent memory or a process crash. The CVE description specifies the out‑of‑bounds read; whether exposed data is sensitive is inferred from the fact that the read may access arbitrary memory.

Any installation of the EGOR:Data::SortedSet::Shared module for Perl running a version earlier than 0.03 is affected. Applications that use this module to maintain ordered sets backed by the shared file are at risk if the module is attached without the later safeguards.

The vulnerability carries a CVSS score of 9.1, indicating a severe weakness. The EPSS score is listed as <1%, suggesting exploitation is currently rare, but the flaw only requires an ability to write to the module’s shared backing file, which is a local privilege. The vulnerability is not yet listed in the CISA KEV catalog. An attacker who controls write access can trigger an out‑of‑bounds read or force a crash, potentially exposing memory contents or causing denial of service. The lack of bounds checks in the query paths is the root cause of the risk.