Parasite hijack in CRIU through malicious rseq critical sections
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
CRIU before 4.2.1 is a Linux checkpoint and restore tool that injects a syscall and int3 sequence at the first executable virtual memory area of the target process. Malicious code can keep an rseq critical section armed over that point, so when CRIU resumes the process, the kernel's restartable-sequence abort redirects execution to an attacker-controlled callback (CWE-705). In container snapshots, the hijacked parasite runs with seccomp disabled and a relaxed AppArmor profile and can supply trusted data to the privileged CRIU process, which may enable higher-privilege code execution. A local user with low privileges and user interaction can exploit this.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
CRIU is a checkpoint and restore tool for Linux. Prior to 4.2.1, CRIU injects a syscall;int3 sequence at the start of the first executable virtual memory area and resumes the target process to execute parasite code. Malicious code in the target process can keep an rseq critical section armed over that injection point so the kernel's restartable-sequence abort redirects execution to an attacker-controlled callback when CRIU resumes the process. In container snapshot environments, the hijacked parasite runs with seccomp disabled and a relaxed AppArmor profile and supplies trusted data to the privileged CRIU process, which can enable higher-privilege code execution. This issue is fixed in version 4.2.1.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| checkpoint-restore | criu | before 4.2.1 | 4.2.1 | Patch available | CNA |
- criu Vendorcheckpoint-restore Affected before 4.2.1 Fixed in 4.2.1 Patch available CNA
Remediation
Upgrade checkpoint-restore CRIU to version 4.2.1, which fixes the issue.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA criu (checkpoint-restore) Fixed in 4.2.1
Timeline
- 2026-11-06 Threatist record created from CVE-2026-73860
- 2026-11-08 Priority changed: MEDIUM → LOW
References
Other 5
- https://github.com/checkpoint-restore/criu/security/advisories/GHSA-fvqj-jvxf-x3wp
- https://github.com/checkpoint-restore/criu/pull/3098
- https://github.com/checkpoint-restore/criu/commit/c34355a7c31494a8be65b32b4410a7539f6c2442
- https://github.com/checkpoint-restore/criu/commit/f7dafedda5075fd6509bda67fbce1622e0c87a27
- https://github.com/checkpoint-restore/criu/releases/tag/v4.2.1
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences