CVE-2021-32740: Regular Expression Denial of Service in Addressable templates
Vulnerability summary
CVE-2021-32740 is a high (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in addressable_project addressable. EPSS estimates a 2.14% chance of exploitation in the next 30 days, higher than 82% of scored vulnerabilities.
Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 2% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 1Timeline
- 06-07-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
Addressable is an alternative implementation to the URI implementation that is part of Ruby's standard library. An uncontrolled resource consumption vulnerability exists after version 2.3.0 through version 2.7.0. Within the URI template implementation in Addressable, a maliciously crafted template may result in uncontrolled resource consumption, leading to denial of service when matched against a URI. In typical usage, templates would not normally be read from untrusted user input, but nonetheless, no previous security advisory for Addressable has cautioned against doing this. Users of the parsing capabilities in Addressable but not the URI template capabilities are unaffected. The vulnerability is patched in version 2.8.0. As a workaround, only create Template objects from trusted sources that have been validated not to produce catastrophic backtracking.
CVSS metrics
7 scores · 6 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · RubygemsEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · AlpineEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
2.14%
Chance of exploitation in the next 30 days
Percentile
82%
Versus all other CVEs
30-day change
Decrease -0.06 pp
From 2.20% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Opensuse2 products
- ruby3.2-rubygem-http&distro=openSUSE Tumbleweed< 5.1.0-1.4
- rubygem-http&distro=openSUSE Tumbleweed< 5.1.0-1.1
Suse2 products
- rubygem-addressable&distro=SUSE OpenStack Cloud Crowbar 8< 2.3.6-3.3.3
- rubygem-addressable&distro=SUSE OpenStack Cloud Crowbar 9< 2.3.6-4.3.3
Addressable_project1 product
- addressable≥ 2.3.0, < 2.8.0
Alpine1 product
- ruby-addressable≥ 2.3.0, < 2.8.0-r0
Debian1 product
- ruby-addressable< 2.7.0-2
Fedoraproject1 product
- fedoraEOL33 | 34
Mageia1 product
- ruby-addressable< 2.7.0-1.1.mga8
RubyGems1 product
- addressable≥ 2.3.0, < 2.8.0
Sporkmonger1 product
- addressable> 2.3.0, ≤ 2.7.0
Ubuntu1 product
- ruby-addressableAll versions (No fix recorded)
10 vendors · 12 products
References
24 links- github.com/sporkmonger/addressable/security/advisories/GHSA-jxhc-q857-3j6gX Refsource CONFIRMREPORTWEBThird Party Advisory
- github.com/sporkmonger/addressable/commit/0d8a3127e35886ce9284810a7f2438bff6b43cbcX Refsource MISCREPORTWEBPatchRelease NotesThird Party Advisory
