CVE-2026-1979
Description
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| debian | bookworm | affected | |
| debian | bullseye | affected | |
| debian | forky | affected | |
| debian | sid | affected | |
| debian | trixie | affected | |
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| mruby | mruby | {"endIncluding":"3.4.0"} | |
References
- https://github.com/mruby/mruby/
- https://github.com/mruby/mruby/issues/6701
- https://github.com/mruby/mruby/issues/6701#issue-3802609843
- https://github.com/sysfce2/mruby/commit/e50f15c1c6e131fa7934355eb02b8173b13df415
- https://vuldb.com/?ctiid.344501
- https://vuldb.com/?id.344501
- https://vuldb.com/?submit.743377
- https://security-tracker.debian.org/tracker/CVE-2026-1979
CWEs
CWE-119 CWE-416
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.