# CVE-2025-11683: Information disclosure in YAML::Syck

> Attackers can read adjacent memory via out-of-bounds read in YAML::Syck when processing complex YAML files, potentially disclosing sensitive information.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Oct 2025
- **Updated:** 16 Oct 2025
- **Also known as:** AZL-109466, AZL-109514, BELL-CVE-2025-11683, DEBIAN-CVE-2025-11683, GHSA-gr2g-vmxj-5cv8, UBUNTU-CVE-2025-11683, USN-7844-1, openSUSE-SU-2026:10746-1

## What is CVE-2025-11683?

CVE-2025-11683 is a medium-severity vulnerability in TODDR YAML::Syck, published on 16 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

YAML::Syck versions before 1.36 for Perl has missing null-terminators which causes out-of-bounds read and potential information disclosure

Missing null terminators in token.c leads to but-of-bounds read which allows adjacent variable to be read

The issue is seen with complex YAML files with a hash of all keys and empty values.  There is no indication that the issue leads to accessing memory outside that allocated to the module.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2025-11683?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `perl-YAML-Syck` | openSUSE:Tumbleweed | All versions | 1.450.0-1.1 |

Products: Toddr Yaml\.

## How do I fix CVE-2025-11683?

Upgrade to a fixed version.

## Is CVE-2025-11683 being exploited?

There is no known exploitation of CVE-2025-11683 in the wild and no public exploit code.

## Other vulnerabilities in TODDR YAML::Syck

- [CVE-2026-4177](https://insights.sbomify.com/CVE-2026-4177/): Memory corruption in YAML::Syck (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-11683 and fix it if it is affected.

What it is: CVE-2025-11683 is a medium-severity vulnerability in TODDR YAML::Syck, published on 16 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-11683 in the wild and no public exploit code.

Affected product: TODDR YAML::Syck. 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-2025-11683/ (Markdown: https://insights.sbomify.com/CVE-2025-11683/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-11683
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-11683
- OSV: https://osv.dev/vulnerability/CVE-2025-11683

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-11683/
Summaries are generated and may contain mistakes; the official description above is the record.