CVE-2026-88358: simdjson version 4.6.1 has a one-byte out-of-bounds read
Affects simdjsonSource CVE Database V5
Not known to be exploited · CVSS 6.5 Medium.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 33% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubsimdjson/simdjsonpkg:github/simdjson/simdjsonOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is available, avoid processing untrusted or truncated JSON documents with simdjson 4.6.1 or implement input validation to ensure JSON completeness.
Description
simdjson version 4.6.1 has a one-byte out-of-bounds read vulnerability in the dom::parser::parse_unpadded() function. This occurs when parsing a specially crafted truncated JSON document that closes a nested array or object at the end, causing an access beyond the input buffer. The vulnerability can lead to application termination and denial of service.