mruby array.c ary_fill_exec out-of-bounds write
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
A weakness has been identified in mruby 3.4.0. This vulnerability affects the function ary_fill_exec of the file mrbgems/mruby-array-ext/src/array.c. Executing a manipulation of the argument start/length can lead to out-of-bounds write. The attack needs to be launched locally. The exploit has been made available to the public and could be used for attacks. This patch is called 93619f06dd378db6766666b30c08978311c7ec94. It is best practice to apply a patch to resolve this issue.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | mruby | 3.4.0 | — | No fix listed | CNA |
- mruby Vendor— Affected 3.4.0 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2025-12875
- 2026-10-03 Alias added: GHSA-q269-xqww-45mm
References
More Mruby vulnerabilities
- TI-2022-00033 Heap-based Buffer Overflow in mruby/mruby CVSS 3.1CRITICAL 9.8
- TI-2026-01636 mruby JMPNOT-to-JMPIF Optimization vm.c mrb_vm_exec use after free CVSS 4.0MEDIUM 4.8
- TI-2025-06567 mruby nregs codegen.c scope_new heap-based overflow CVSS 4.0MEDIUM 4.8
- TI-2018-07224 In versions of mruby up to and including 1.4.0, an integer overflow exists in… CVSS 3.1CRITICAL 9.8
- TI-2022-01100 Use-After-Free in str_escape in mruby/mruby in mruby/mruby CVSS 3.1CRITICAL 9.8
- TI-2020-12486 mruby through 2.1.2-rc has a heap-based buffer overflow in the mrb_yield_with_class… CVSS 3.1CRITICAL 9.8
Sources
- CVE-2025-12875 · CVE Program
- CVE-2025-12875 · NVD
- FIRST EPSS
- GHSA-q269-xqww-45mm · GitHub Advisory Database · CC BY 4.0
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