CVE-2021-22960: The parse function in llhttp < 2.1.4 and < 6.0.6

Q: How urgent is CVE-2021-22960?

Priority 59/100. Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

This week

MEDIUM 6.5REMOTEWATCHLISTUPGRADEDOWNGRADEMITIGATE

CVE-2021-22960 is a medium-severity flaw (CVSS 6.5) affecting llhttp, graalvm, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The parse function in llhttp < 2.1.4 and < 6.0.6. ignores chunk extensions when parsing the body of chunked requests. This leads to HTTP Request Smuggling (HRS) under certain conditions.

Why this priority

Public exploit reference
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.5% (top 15%)
CISA exploited list	No
Weakness	CWE-444
Published	2021-11-03
Last modified	2026-06-17

Publisher (CNA): HackerOne · Vendor: debian · llhttp · oracle

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

Am I affected?

Timeline

2021-11-03 20:15 UTCPublished CVE record published
2026-06-17 03:38 UTCUpdated Record last modified

llhttp llhttp UPGRADE

Affected: < 2.1.4 · >= 3.0.0 and < 6.0.6

Fixed in: 2.1.4, 6.0.6

Safe to downgrade to: a release before 3.0.0

1. Check installed version

npm ls llhttp

2. UPGRADE to 2.1.4

npm install llhttp@">=2.1.4"

3. If no update is available yet, DOWNGRADE to a release before 3.0.0

npm view llhttp versions npm install llhttp@"<3.0.0"

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.

oracle graalvm DOWNGRADE

Affected: 20.3.4 · 21.3.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 20.3.4

1. Check installed version

apt-cache policy graalvm || rpm -q graalvm || graalvm --version

2. No fixed release: DOWNGRADE to a release before 20.3.4 (Debian / Ubuntu)

apt-cache madison graalvm sudo apt install graalvm=<VERSION_BEFORE_20.3.4> sudo apt-mark hold graalvm

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list graalvm sudo dnf downgrade graalvm-<VERSION_BEFORE_20.3.4> sudo dnf versionlock add graalvm

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.

debian debian linux MITIGATE

Affected: 11.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 11.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

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-2021-22960?

llhttp: upgrade to 2.1.4, 6.0.6; graalvm: downgrade or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-22960 being exploited?

CVE-2021-22960 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-2021-22960 affect?

CVE-2021-22960 affects llhttp, graalvm, debian linux. Severity is medium (CVSS 6.5). The parse function in llhttp < 2.1.4 and < 6.0.6. ignores chunk extensions when parsing the body of chunked requests. This leads to HTTP Request Smuggling (HRS) under certain conditions.

How urgent is CVE-2021-22960?

Priority 59/100. Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Debian vulnerabilities

Related CVEs

CVE-2022-35256 MEDIUM 6.5 UPGRADE UPGRADE The llhttp parser in the http module in Node v18.7.0 does not correctly handle header fields that are not term
CVE-2022-32215 MEDIUM 6.5 UPGRADE UPGRADE The llhttp parser <v14.20.1, <v16.17.1 and <v18.9.1 in the http module in Node.js does not correctly handle mu
CVE-2022-32214 MEDIUM 6.5 UPGRADE UPGRADE The llhttp parser <v14.20.1, <v16.17.1 and <v18.9.1 in the http module in Node.js does not strictly use the CR
CVE-2022-32213 MEDIUM 6.5 UPGRADE UPGRADE The llhttp parser <v14.20.1, <v16.17.1 and <v18.9.1 in the http module in Node.js does not correctly parse and
CVE-2021-22959 MEDIUM 6.5 UPGRADE DOWNGRADE The parser in accepts requests with a space (SP) right after the header name before the colon

References

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