Data::RingBuffer::Shared versions before 0.04 for Perl allow a stack buffer overflow via an unvalidated elem_size in ring_read_seq

Summary

Data::RingBuffer::Shared versions before 0.04 for Perl allow a stack buffer overflow via an unvalidated elem_size in ring_read_seq. The attach-time validator ring_validate_header checks the capacity-overflow and total_size consistency of the header but never caps elem_size against the destination size. ring_read_seq does memcpy(out, ring_slot(h, seq), elem_size) with elem_size read raw from the mmap'd segment, copying into a fixed 8-byte destination scalar. An elem_size larger than 8 bytes writes past the destination. A local peer that can write the backing file can leave the header valid while setting a large elem_size, so the next read copies a file-controlled length into the fixed 8-byte stack buffer, corrupting adjacent stack frames.

Timeline

1. Jul 21, 2026, 7:04 PM UTCCVE published
2. Jul 22, 2026, 7:33 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: total

3. Jul 22, 2026, 7:33 PM UTCRecord last updated

Affected versions

• Data-RingBuffer-Shared

  fixed in 0.04

References 2