Medium (6.5). EPSS 0.4% chance of exploitation in the next 30 days.
simdjson 4.6.1 contains a one-byte out-of-bounds read vulnerability in dom::parser::parse_unpadded(). A specially crafted truncated JSON document whose final structural token closes a nested array or object can cause json_iterator::walk_document() to access buf[len] after the input buffer has been exhausted. This results in a heap out-of-bounds read and may cause application termination, leading to denial of service.
Severity
CVSS 3.1
6.5 medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
EPSS
0.4% chance of exploitation in the next 30 days; higher than 33% of CVEs (scores of 2026-10-31)