CVE-2026-116733 json
flatcc through 0.6.4 Out-of-Bounds Read via __flatcc_json_parser_number
published 14d ago modified 7d ago also EUVD-2026-110481
- cvss
- 3.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 36%
- public exploits
- 0
- none known
Summary
flatcc through 0.6.4 contains an out-of-bounds read vulnerability in __flatcc_json_parser_number that allows attackers to read past the input buffer via numbers ending in a decimal point. Attackers can supply untrusted JSON ending immediately after a decimal point to generated parsers, crashing applications when the buffer ends at an unmapped page.
Patch / fix
Is CVE-2026-116733 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 7d ago
Exploit prediction
0.42% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- hackmd.io https://hackmd.io/@haindpwn/cve-2026-116733-116734-flatcc-json-number-oob-read referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.3 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |
| CNA | 3.1 | 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L |
| CNA | 4.0 | 6.3 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- dvidelabs flatcc
Classification
- Weakness
-
- CWE-125 Out-of-bounds Read
References
-
github.com
/dvidelabs/flatcc/commit/356792dc155a9e685acdfe0ec1e209bdadcb4ab9
patch
-
hackmd.io
/@haindpwn/cve-2026-116733-116734-flatcc-json-number-oob-read
exploit
-
github.com
/dvidelabs/flatcc
product
-
github.com
/dvidelabs/flatcc/blob/v0.6.4/src/runtime/json_parser.c#L539-L543
technical-description
-
hackmd.io
/@haindpwn/flatcc-json-number-oob-read
third-party-advisory
-
vulncheck.com
/advisories/flatcc-through-0.6.4-out-of-bounds-read-via-flatcc-json-parser-number
third-party-advisory
Sources
- CVE List CVE-2026-116733
- NVD CVE-2026-116733
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.