CVE-2021-29481: Ratpack is a toolkit for creating web applications

Q: How do I fix CVE-2021-29481?

ratpack: upgrade to 1.9.0. Exact commands for each OS are on this page.

Q: Is CVE-2021-29481 being exploited?

CVE-2021-29481 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-2021-29481 affect?

CVE-2021-29481 affects ratpack. Severity is medium (CVSS 6.5). Ratpack is a toolkit for creating web applications. In versions prior to 1.9.0, the default configuration of client side sessions results in unencrypted, but signed, data being set as cookie values. This means that if something sensitive go

Q: How urgent is CVE-2021-29481?

Priority 33/100. No elevated risk signals yet.

Routine

MEDIUM 6.5UPGRADE

CVE-2021-29481 is a medium-severity flaw (CVSS 6.5) affecting ratpack. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Ratpack is a toolkit for creating web applications. In versions prior to 1.9.0, the default configuration of client side sessions results in unencrypted, but signed, data being set as cookie values. This means that if something sensitive goes into the session, it could be read by something with access to the cookies. For this to be a vulnerability, some kind of sensitive data would need to be stored in the session and the session cookie would hav

Why this priority

No elevated risk signals yet

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	Required
EPSS exploit chance	0.5% (top 60%)
CISA exploited list	No
Weakness	CWE-312
Published	2021-06-29
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: ratpack project

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

Am I affected?

Timeline

2021-06-29 19:15 UTCPublished CVE record published
2026-06-17 03:47 UTCUpdated Record last modified

ratpack project ratpack UPGRADE

Affected: < 1.9.0

Fixed in: 1.9.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 1.9.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade ratpack

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade ratpack

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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-2021-29481?

ratpack: upgrade to 1.9.0. Exact commands for each OS are on this page.

Is CVE-2021-29481 being exploited?

CVE-2021-29481 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-2021-29481 affect?

CVE-2021-29481 affects ratpack. Severity is medium (CVSS 6.5). Ratpack is a toolkit for creating web applications. In versions prior to 1.9.0, the default configuration of client side sessions results in unencrypted, but signed, data being set as cookie values. This means that if something sensitive go

How urgent is CVE-2021-29481?

Priority 33/100. No elevated risk signals yet.

Related CVEs

CVE-2021-29485 CRITICAL 9.9 UPGRADE Ratpack is a toolkit for creating web applications
CVE-2021-29480 MEDIUM 4.4 UPGRADE Ratpack is a toolkit for creating web applications
CVE-2021-29479 HIGH 7.0 UPGRADE Ratpack is a toolkit for creating web applications
CVE-2019-10770 MEDIUM 6.1 UPGRADE All versions of io.ratpack:ratpack-core from 0.9.10 inclusive and before 1.7.6 are vulnerable to Cross-site Sc

References

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