CVE-2026-33532: `yaml` is a YAML parser and serialiser for JavaScript

Q: How do I fix CVE-2026-33532?

yaml: upgrade to 1.10.3, 2.8.3. Exact commands for each OS are on this page.

Q: Is CVE-2026-33532 being exploited?

CVE-2026-33532 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-33532 affect?

CVE-2026-33532 affects yaml. Severity is medium (CVSS 4.3). `yaml` is a YAML parser and serialiser for JavaScript. Parsing a YAML document with a version of `yaml` on the 1.x branch prior to 1.10.3 or on the 2.x branch prior to 2.8.3 may throw a RangeError due to a stack overflow. The node resolutio

Q: How urgent is CVE-2026-33532?

Priority 31/100. Public exploit reference

Routine

MEDIUM 4.3UPGRADE

CVE-2026-33532 is a medium-severity flaw (CVSS 4.3) affecting yaml. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

`yaml` is a YAML parser and serialiser for JavaScript. Parsing a YAML document with a version of `yaml` on the 1.x branch prior to 1.10.3 or on the 2.x branch prior to 2.8.3 may throw a RangeError due to a stack overflow. The node resolution/composition phase uses recursive function calls without a depth bound. An attacker who can supply YAML for parsing can trigger a `RangeError: Maximum call stack size exceeded` with a small payload (~2–10 KB).

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	4.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.5% (top 58%)
CISA exploited list	No
Weakness	CWE-674
Published	2026-03-26
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: eemeli

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-26 20:16 UTCPublished CVE record published
2026-06-17 10:37 UTCUpdated Record last modified

eemeli yaml UPGRADE

Affected: >= 1.0.0 and < 1.10.3 · >= 2.0.0 and < 2.8.3

Fixed in: 1.10.3, 2.8.3

Safe to downgrade to: a release before 1.0.0

1. Check installed version

npm ls yaml

2. UPGRADE to 1.10.3

npm install yaml@">=1.10.3"

3. If no update is available yet, DOWNGRADE to a release before 1.0.0

npm view yaml versions npm install yaml@"<1.0.0"

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-33532?

yaml: upgrade to 1.10.3, 2.8.3. Exact commands for each OS are on this page.

Is CVE-2026-33532 being exploited?

CVE-2026-33532 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-33532 affect?

CVE-2026-33532 affects yaml. Severity is medium (CVSS 4.3). `yaml` is a YAML parser and serialiser for JavaScript. Parsing a YAML document with a version of `yaml` on the 1.x branch prior to 1.10.3 or on the 2.x branch prior to 2.8.3 may throw a RangeError due to a stack overflow. The node resolutio

How urgent is CVE-2026-33532?

Priority 31/100. Public exploit reference

References

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