# CVE-2026-57075: Memory corruption in YAML::Syck

> An out-of-bounds read in the YAML::Syck Perl library allows attackers to disclose memory or cause crashes via crafted binary YAML data.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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:** 16 Jul 2026
- **Updated:** 17 Jul 2026
- **Also known as:** ALPINE-CVE-2026-57075, AZL-109517, AZL-92913, BELL-CVE-2026-57075, DEBIAN-CVE-2026-57075, GHSA-fwh5-hwhp-qgp4, UBUNTU-CVE-2026-57075

## What is CVE-2026-57075?

CVE-2026-57075 is a critical memory corruption vulnerability in TODDR YAML::Syck, published on 16 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

YAML::Syck versions before 1.47 for Perl allow an out-of-bounds read via a signed-char lookup-table index in syck_base64dec.

The base64 decoder in the bundled libsyck indexes the 256-entry static table b64_xtable with a signed char, so any !!binary byte >= 0x80 sign-extends to a negative index and reads before the table. The decoder receives the raw bytes of any !!binary node, a standard YAML type not gated by $LoadBlessed or $LoadCode, so it is reached on the default Load path.

Any caller that runs Load or LoadFile on an untrusted document containing a !!binary scalar with a high-bit byte triggers the read, and the value read can surface in the decoded result.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-57075?


## How do I fix CVE-2026-57075?

Upgrade to a fixed version.

## Is CVE-2026-57075 being exploited?

There is no known exploitation of CVE-2026-57075 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-57075 and fix it if it is affected.

What it is: CVE-2026-57075 is a critical memory corruption vulnerability in TODDR YAML::Syck, published on 16 Jul 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-2026-57075 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-2026-57075/ (Markdown: https://insights.sbomify.com/CVE-2026-57075/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57075
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57075
- OSV: https://osv.dev/vulnerability/CVE-2026-57075

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-57075/
Summaries are generated and may contain mistakes; the official description above is the record.