rapidyaml through 0.16.0 contains an out-of-bounds write vulnerability in ParseEngine::_add_annotation() that allows
Source GCVE Database
Not known to be exploited · CVSS 6.9 Medium.
Data as of 2 Nov 2026, 16:44 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 6.9 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 6.1 |
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 2 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 2 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| biojppmrapidyaml | Affected
| Fixed in– |
GitHubrapidyamlpkg:github/rapidyamlOther 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
Since the vulnerability requires user interaction and local access, avoid processing untrusted YAML inputs with rapidyaml versions through 0.16.0. Monitor vendor advisories for updates or patches. Until a fix is available, restrict usage to trusted YAML sources or consider alternative YAML parsers without this vulnerability.
Description
rapidyaml versions through 0.16.0 have an out-of-bounds write vulnerability in the ParseEngine::_add_annotation() function. This flaw allows attackers to corrupt memory by providing YAML input with excessive anchors or tags, which overflow a fixed-size annotation array. The overflow can corrupt stack memory and cause the process to crash.
References
- nvd.nist.gov/vuln/detail/CVE-2026-120455 (opens in a new tab)
- github.com/biojppm/rapidyaml/issues/680 (opens in a new tab)
- github.com/biojppm/rapidyaml/blob/v0.16.0/src/c4/yml/parse_engine.def.hpp (opens in a new tab)
- github.com/biojppm/rapidyaml/blob/v0.16.0/src/c4/yml/parse_engine.def.hpp (opens in a new tab)
- github.com/biojppm/rapidyaml/blob/v0.16.0/src/c4/yml/parse_engine.hpp (opens in a new tab)
- github.com/biojppm/rapidyaml/releases/tag/v0.16.0 (opens in a new tab)
- hackmd.io/@haindpwn/rapidyaml-parser-annotation-oob-write (opens in a new tab)
- vulncheck.com/advisories/rapidyaml-through-0.16.0-out-of-bounds-write-via-parseengine-add-annotation (opens in a new tab)