# CVE-2026-47770: jq: stack overflow in deep structural equality

> Attackers can cause denial of service in jq by providing deeply nested JSON arrays that trigger stack exhaustion during equality comparisons.

- **Severity:** Medium 6.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 25 Jun 2026
- **Updated:** 26 Jun 2026
- **Also known as:** ALPINE-CVE-2026-47770, AZL-90273, BELL-CVE-2026-47770, CLSA-2026-1782901522, DEBIAN-CVE-2026-47770, ECHO-b834-a843-3668, GHSA-3pgx-frr7-3jxp, UBUNTU-CVE-2026-47770

## What is CVE-2026-47770?

CVE-2026-47770 is a medium-severity denial of service vulnerability in jqlang jq, published on 25 Jun 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

jq is a command-line JSON processor. Prior to 1.8.2, comparing two sufficiently deeply nested arrays with the == operator exhausts the C stack on jq's ordinary command-line surface, resulting in denial of service via stack exhaustion (uncontrolled recursion). The crash occurs in jq's recursive structural comparison code, with the recursion repeating through jvp_array_equal() and jv_equal() in src/jv.c when comparing deeply nested arrays; a nearby sort comparator path through jv_cmp() in src/jv_aux.c overflows the stack at a larger nesting depth from  the same missing recursion guard. Anyone running jq comparisons on attacker-controlled deeply nested JSON values, or embedding jq in a context  where untrusted data can reach the == comparison path, is affected. This vulnerability is fixed in 1.8.2.

Weakness: CWE-674 (Uncontrolled Recursion)

## Which versions are affected by CVE-2026-47770?

It affects 1 product.


Products: Jqlang Jq.

## How do I fix CVE-2026-47770?

Upgrade to a fixed version.

## Is CVE-2026-47770 being exploited?

There is no known exploitation of CVE-2026-47770 in the wild and no public exploit code.

## Other vulnerabilities in jqlang jq

- [CVE-2026-32316](https://insights.sbomify.com/CVE-2026-32316/): jq: Integer overflow in jvp_string_append() allows Heap-based Buffer Overflow (high 8.2)
- [CVE-2024-53427](https://insights.sbomify.com/CVE-2024-53427/): Memory corruption in jq (high 8.1)
- [CVE-2025-48060](https://insights.sbomify.com/CVE-2025-48060/): AddressSanitizer: stack-buffer-overflow in jq_fuzz_execute (jv_string_vfmt) (high 7.7)
- [CVE-2023-49355](https://insights.sbomify.com/CVE-2023-49355/): Memory corruption in n/a (high 7.5)
- [CVE-2026-49839](https://insights.sbomify.com/CVE-2026-49839/): jq --rawfile invalid-state reuse after String too long causes heap-buffer-overflow (high 7.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-47770 and fix it if it is affected.

What it is: CVE-2026-47770 is a medium-severity denial of service vulnerability in jqlang jq, published on 25 Jun 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-47770 in the wild and no public exploit code.

Affected product: jqlang jq. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-47770/ (Markdown: https://insights.sbomify.com/CVE-2026-47770/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47770
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47770
- OSV: https://osv.dev/vulnerability/CVE-2026-47770

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47770/
Summaries are generated and may contain mistakes; the official description above is the record.