CVE-2023-28755: A ReDoS issue was discovered in the URI component through 0.12.0 in Ruby through 3.2.1

Q: How do I fix CVE-2023-28755?

uri: upgrade to newer than 0.10.0; debian linux: mitigate or apply the listed mitigation; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2023-28755 being exploited?

CVE-2023-28755 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-2023-28755 affect?

CVE-2023-28755 affects uri, debian linux, fedora. Severity is medium (CVSS 5.3). A ReDoS issue was discovered in the URI component through 0.12.0 in Ruby through 3.2.1. The URI parser mishandles invalid URLs that have specific characters. It causes an increase in execution time for parsing strings to URI objects. The fi

Q: How urgent is CVE-2023-28755?

Priority 50/100. Remotely exploitable, no login, no user action; On your watchlist

This month

MEDIUM 5.3REMOTEWATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2023-28755 is a medium-severity flaw (CVSS 5.3) affecting uri, debian linux, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A ReDoS issue was discovered in the URI component through 0.12.0 in Ruby through 3.2.1. The URI parser mishandles invalid URLs that have specific characters. It causes an increase in execution time for parsing strings to URI objects. The fixed versions are 0.12.1, 0.11.1, 0.10.2 and 0.10.0.1.

Why this priority

Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.6% (top 14%)
CISA exploited list	No
Weakness	CWE-1333
Published	2023-03-31
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: debian · fedoraproject · ruby-lang

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

Am I affected?

Timeline

2023-03-31 04:15 UTCPublished CVE record published
2026-06-17 05:48 UTCUpdated Record last modified

ruby-lang uri UPGRADE

Affected: <= 0.10.0 · 0.10.1 · 0.11.0 · 0.12.0

Fixed in: newer than 0.10.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 0.10.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade uri

Note

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

debian debian linux MITIGATE

Affected: 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 10.0

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.

fedoraproject fedora MITIGATE

Affected: 36 · 37 · 38

Fixed in: no fixed release known

Safe to downgrade to: a release before 36

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-2023-28755?

uri: upgrade to newer than 0.10.0; debian linux: mitigate or apply the listed mitigation; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-28755 being exploited?

CVE-2023-28755 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-2023-28755 affect?

CVE-2023-28755 affects uri, debian linux, fedora. Severity is medium (CVSS 5.3). A ReDoS issue was discovered in the URI component through 0.12.0 in Ruby through 3.2.1. The URI parser mishandles invalid URLs that have specific characters. It causes an increase in execution time for parsing strings to URI objects. The fi

How urgent is CVE-2023-28755?

Priority 50/100. Remotely exploitable, no login, no user action; On your watchlist

Software pages

Debian vulnerabilities · Ruby vulnerabilities

Related CVEs

CVE-2025-61594 HIGH 7.5 UPGRADE URI is a module providing classes to handle Uniform Resource Identifiers
CVE-2025-27221 LOW 3.2 UPGRADE In the URI gem before 1.0.3 for Ruby, the URI handling methods (URI.join, URI#merge, URI#+) have an inadverten
CVE-2023-36617 MEDIUM 5.3 UPGRADE A ReDoS issue was discovered in the URI component before 0.12.2 for Ruby
CVE-2023-28628 MEDIUM 5.4 UPGRADE lambdaisland/uri is a pure Clojure/ClojureScript URI library

References

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