# CVE-2026-97370: Junrar: RarVM VM_JMP maxOpCount bypass causes infinite CPU loop during RAR4 extraction

> A crafted RAR4 archive causes an infinite CPU loop in the Junrar library during extraction, leading to denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Oct 2026
- **Updated:** 16 Oct 2026
- **Also known as:** ECHO-f3d7-a91d-ed23, GHSA-h9h9-2rmf-rvhp

## What is CVE-2026-97370?

CVE-2026-97370 is a high-severity denial of service vulnerability in junrar, published on 15 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Junrar is an open source Java RAR archive library. Prior to 7.6.1, RarVM.ExecuteCode in src/main/java/com/github/junrar/unpack/vm/RarVM.java can repeatedly execute a VM_JMP instruction whose target is greater than or equal to the prepared program's codeSize. The setIP() function returns success without changing the instruction pointer or decrementing maxOpCount, and the jump handler continues before loop-end accounting, leaving both values unchanged. A crafted RAR4 archive can therefore keep an extraction thread in an infinite CPU loop and exhaust archive-processing worker capacity. The RAR virtual machine does not expose native process execution, so the supported impact is availability loss rather than code execution. This issue is fixed in version 7.6.1.

Weakness: CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2026-97370?

2 open source packages ship an affected version, including com.github.junrar:junrar.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `com.github.junrar:junrar` | Maven | All versions | 7.6.1 |
| `com.github.junrar:junrar` | Maven | All versions | 7.6.1 |

## How do I fix CVE-2026-97370?

Upgrade com.github.junrar:junrar to 7.6.1 or later.

## Is CVE-2026-97370 being exploited?

There is no known exploitation of CVE-2026-97370 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97370 and fix it if it is affected.

What it is: CVE-2026-97370 is a high-severity denial of service vulnerability in junrar, published on 15 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-97370 in the wild and no public exploit code.

Affected packages and fixed versions:
- com.github.junrar:junrar (Maven): affected all versions; fixed in 7.6.1
- com.github.junrar:junrar (Maven): affected all versions; fixed in 7.6.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-97370/ (Markdown: https://insights.sbomify.com/CVE-2026-97370/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97370
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97370
- OSV: https://osv.dev/vulnerability/CVE-2026-97370

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97370/
Summaries are generated and may contain mistakes; the official description above is the record.