VulnerabilityPublished 29 Jun 2023Updated 4 Nov 2025

CVE-2023-36617: CVE-2023-36617 is a Regular Expression Denial of Service (ReDoS) vulnerability in the URI component

Source CVE Database V5

Mentioned vulnerabilities

CVE-2023-28755

Not known to be exploited · fixed in 0.12.2 : update Ruby when convenient.

Data as of 26 Oct 2026, 17:16 UTC

Severity

Medium

Rated Medium by the CNA (mitre) · No CVSS score from NVD or the CNA

EPSS: 1.6% chance of exploitation in 30 days – higher than 77% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Affects: Ruby before 0.12.2
Patch: Available – fixed in 0.12.2, 0.10.3

Exploitation evidence

Disclosed: evidence found.
CVE published 29 Jun 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

Upgrading to Ruby URI component versions 0.10.3 or 0.12.2 or later fully addresses this vulnerability. Users should apply these official fixes to mitigate the risk. No additional vendor advisory indicates alternative mitigations or that no action is required.

Description

CVE-2023-36617 is a Regular Expression Denial of Service (ReDoS) vulnerability in the URI component for Ruby versions before 0.12.2. The URI parser mishandles invalid URLs containing specific characters, causing increased execution time when parsing strings to URI objects. This issue is due to an incomplete fix for a previous vulnerability (CVE-2023-28755). Versions 0.10.3 and 0.12.2 include fixes for this vulnerability.

Impact

The vulnerability can cause a denial of service condition by significantly increasing the time required to parse certain crafted invalid URLs. This can degrade application performance or cause resource exhaustion during URI parsing operations.

Summary

This vulnerability affects the URI parser in Ruby's URI component prior to version 0.12.2. The parser improperly handles certain invalid URLs with specific characters, leading to increased execution time during URI parsing via rfc2396_parser.rb and rfc3986_parser.rb. The issue stems from an incomplete remediation of CVE-2023-28755. Fixed versions are 0.10.3 and 0.12.2.

References

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 25 Oct 2026, 22:42 UTC

Technical details

References

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