# CVE-2026-110677: Cpanel::JSON::XS versions from 4.28 before 4.80 for Perl leak the array collecting duplicate key values under dupkeys_as_arrayref in decode_hv.

> Attackers can exhaust process memory by repeatedly decoding untrusted JSON with duplicate keys when dupkeys_as_arrayref is enabled.

- **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:** 19 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** AZL-109863, DEBIAN-CVE-2026-110677, GHSA-mjfh-hmwc-q348, UBUNTU-CVE-2026-110677

## What is CVE-2026-110677?

CVE-2026-110677 is a high-severity denial of service vulnerability, published on 19 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Cpanel::JSON::XS versions from 4.28 before 4.80 for Perl leak the array collecting duplicate key values under dupkeys_as_arrayref in decode_hv.

With dupkeys_as_arrayref, the values of a duplicate object key are collected into a new array. An extra reference is never released, so the array and every value in it outlive the decoded structure. The array also leaks when decoding fails after a duplicate key.

Repeatedly decoding untrusted JSON with a duplicate key holding a large value exhausts process memory.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2026-110677?


## How do I fix CVE-2026-110677?

Upgrade to a fixed version.

## Is CVE-2026-110677 being exploited?

There is no known exploitation of CVE-2026-110677 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-110677 and fix it if it is affected.

What it is: CVE-2026-110677 is a high-severity denial of service vulnerability, published on 19 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-2026-110677 in the wild and no public exploit code.

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-2026-110677/ (Markdown: https://insights.sbomify.com/CVE-2026-110677/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-110677
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-110677
- OSV: https://osv.dev/vulnerability/CVE-2026-110677

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-110677/
Summaries are generated and may contain mistakes; the official description above is the record.