Mruby
CVE-2026-1979
LOW
Severity by source
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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
AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Primary rating from NVD.
CVSS VectorNVD
Lifecycle Timeline
6DescriptionCVE.org
A flaw has been found in mruby up to 3.4.0. This affects the function mrb_vm_exec of the file src/vm.c of the component JMPNOT-to-JMPIF Optimization. Executing a manipulation can lead to use after free. The attack needs to be launched locally. The exploit has been published and may be used. This patch is called e50f15c1c6e131fa7934355eb02b8173b13df415. It is advisable to implement a patch to correct this issue.
AnalysisAI
Use-after-free memory corruption in mruby up to version 3.4.0 within the JMPNOT-to-JMPIF optimization logic allows local attackers with user-level privileges to corrupt memory and potentially execute arbitrary code. Public exploit code exists for this vulnerability, and a patch is available. Affected systems should apply the available security update promptly.
Technical ContextAI
Classified as CWE-119 (Buffer Overflow). Affects Mruby. A flaw has been found in mruby up to 3.4.0. This affects the function mrb_vm_exec of the file src/vm.c of the component JMPNOT-to-JMPIF Optimization. Executing a manipulation can lead to use after free. The attack needs to be launched locally. The exploit has been published and may be used. This patch is called e50f15c1c6e131fa7934355eb02b8173b13df415. It is advisable to implement a patch to correct this issue.
RemediationAI
A vendor patch is available — apply it immediately. Enable ASLR, DEP/NX, and stack canaries where possible.
heap-buffer-overflow in mrb_vm_exec in mruby/mruby in GitHub repository mruby/mruby prior to 3.2. Rated critical severit
Out-of-bounds Read in mrb_get_args in GitHub repository mruby/mruby prior to 3.2. Rated critical severity (CVSS 9.8), th
Use-After-Free in str_escape in mruby/mruby in GitHub repository mruby/mruby prior to 3.2. Rated critical severity (CVSS
Heap-based Buffer Overflow in Homebrew mruby prior to 3.2. Rated critical severity (CVSS 9.8), this vulnerability is rem
mruby is vulnerable to Heap-based Buffer Overflow. Rated critical severity (CVSS 9.8), this vulnerability is remotely ex
mruby through 2.1.2-rc has a heap-based buffer overflow in the mrb_yield_with_class function in vm.c because of incorrec
In mruby 2.1.0, there is a use-after-free in hash_slice in mrbgems/mruby-hash-ext/src/hash-ext.c. Rated critical severit
In mruby 2.1.0, there is a stack-based buffer overflow in mrb_str_len_to_dbl in string.c. Rated critical severity (CVSS
In mruby 2.1.0, there is a use-after-free in hash_values_at in mrbgems/mruby-hash-ext/src/hash-ext.c. Rated critical sev
The init_copy function in kernel.c in mruby 1.4.1 makes initialize_copy calls for TT_ICLASS objects, which allows attack
In versions of mruby up to and including 1.4.0, an integer overflow exists in src/vm.c::mrb_vm_exec() when handling OP_G
use after free in mrb_vm_exec in GitHub repository mruby/mruby prior to 3.2. Rated critical severity (CVSS 9.1), this vu
Same weakness CWE-119 – Buffer Overflow
View allSame technique Buffer Overflow
View allVendor StatusVendor
SUSE
Severity: MediumShare
External POC / Exploit Code
Leaving vuln.today