CVE-2026-33169
published 2026-03-24CVE-2026-33169: Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. `NumberToDelimitedConverter` uses a…
PriorityP428medium5.3CVSS 3.1
AVNACLPRNUINSUCNINAL
EPSS
0.59%
46.2th percentile
Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. `NumberToDelimitedConverter` uses a lookahead-based regular expression with `gsub!` to insert thousands delimiters. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, the interaction between the repeated lookahead group and `gsub!` can produce quadratic time complexity on long digit strings. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.
Affected
10 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | rails | — | — |
| rails | activesupport | < 7.2.3.1 | 7.2.3.1 |
| rails | activesupport | — | — |
| rails | activesupport | — | — |
| rails | activesupport | >= 0 < 7.2.3.1 | 7.2.3.1 |
| rails | activesupport | >= 8.0.0.beta1 < 8.0.4.1 | 8.0.4.1 |
| rails | activesupport | >= 8.1.0.beta1 < 8.1.2.1 | 8.1.2.1 |
| rubyonrails | rails | < 7.2.3.1 | 7.2.3.1 |
| rubyonrails | rails | >= 8.0.0 < 8.0.4.1 | 8.0.4.1 |
| rubyonrails | rails | >= 8.1.0 < 8.1.2.1 | 8.1.2.1 |
CVSS provenance
nvdv3.15.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
nvdv4.06.9MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
osv6.9MEDIUM
vendor_debian6.9MEDIUM
vendor_redhat6.9MEDIUM
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Red Hat
rails: rails-activesupport: Active Support: Denial of Service via crafted long digit strings
vendor_redhat·2026-03-23·CVSS 6.9
CVE-2026-33169 [MEDIUM] CWE-1333 rails: rails-activesupport: Active Support: Denial of Service via crafted long digit strings
rails: rails-activesupport: Active Support: Denial of Service via crafted long digit strings
Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. `NumberToDelimitedConverter` uses a lookahead-based regular expression with `gsub!` to insert thousands delimiters. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, the interaction between the repeated lookahead group and `gsub!` can produce quadratic time complexity on long digit strings. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.
A flaw was found in Active Support, a toolkit of support libraries for the Rails framework. The `NumberToDelimitedConverter` component, responsible for formatting numbers, uses a regular expression that can lead to a significant slowdown when proce
Debian
CVE-2026-33169: rails - Active Support is a toolkit of support libraries and Ruby core extensions extrac...
vendor_debian·2026·CVSS 6.9
CVE-2026-33169 [MEDIUM] CVE-2026-33169: rails - Active Support is a toolkit of support libraries and Ruby core extensions extrac...
Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. `NumberToDelimitedConverter` uses a lookahead-based regular expression with `gsub!` to insert thousands delimiters. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, the interaction between the repeated lookahead group and `gsub!` can produce quadratic time complexity on long digit strings. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.
Scope: local
bookworm: open
bullseye: open
forky: open
sid: open
trixie: open
OSV
CVE-2026-33169: Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework
osv·2026-03-24·CVSS 6.9
CVE-2026-33169 [MEDIUM] CVE-2026-33169: Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework
Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. `NumberToDelimitedConverter` uses a lookahead-based regular expression with `gsub!` to insert thousands delimiters. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, the interaction between the repeated lookahead group and `gsub!` can produce quadratic time complexity on long digit strings. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.
OSV
Rails Active Support has a possible ReDoS vulnerability in number_to_delimited
osv·2026-03-23
CVE-2026-33169 [MEDIUM] Rails Active Support has a possible ReDoS vulnerability in number_to_delimited
Rails Active Support has a possible ReDoS vulnerability in number_to_delimited
### Impact
`NumberToDelimitedConverter` used a regular expression with `gsub!` to insert thousands delimiters. This could produce quadratic time complexity on long digit strings.
### Releases
The fixed releases are available at the normal locations.
GHSA
Rails Active Support has a possible ReDoS vulnerability in number_to_delimited
ghsa·2026-03-23
CVE-2026-33169 [MEDIUM] CWE-1333 Rails Active Support has a possible ReDoS vulnerability in number_to_delimited
Rails Active Support has a possible ReDoS vulnerability in number_to_delimited
### Impact
`NumberToDelimitedConverter` used a regular expression with `gsub!` to insert thousands delimiters. This could produce quadratic time complexity on long digit strings.
### Releases
The fixed releases are available at the normal locations.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-33169 rails: rails-activesupport: Active Support: Denial of Service via crafted long digit strings
bugzilla·2026-03-24·CVSS 5.3
CVE-2026-33169 [MEDIUM] CVE-2026-33169 rails: rails-activesupport: Active Support: Denial of Service via crafted long digit strings
CVE-2026-33169 rails: rails-activesupport: Active Support: Denial of Service via crafted long digit strings
Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. `NumberToDelimitedConverter` uses a lookahead-based regular expression with `gsub!` to insert thousands delimiters. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, the interaction between the repeated lookahead group and `gsub!` can produce quadratic time complexity on long digit strings. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.
Wiz
CVE-2026-33169 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 4.8
CVE-2026-33169 [MEDIUM] CVE-2026-33169 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-33169 :
Ruby vulnerability analysis and mitigation
NumberToDelimitedConverter
gsub!
gsub!
Source : NVD
## 6.9
Score
Published March 24, 2026
Severity MEDIUM
CNA Score 6.9
Affected Technologies
Ruby
Rails
Has Public Exploit No
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 4.9
Exploitation Probability (EPSS) N/A
Affected packages and libraries
ruby4.0-activesupport
cpe:2.3:a:rubyonrails:rails
Sources
Chainguard Has Fix Added at: Mar 25, 2026
Debian 11, 12, 13, 14 Severity MEDIUM No Fix Added at: Mar 26, 2026
Echo Severity MEDIUM No Fix Added at: Mar 26, 2026
RubyGems Severity MEDIUM Has Fix Added at: Mar 24, 2026
MinimOS Severity MEDIUM Has Fix Added at: Mar 24, 2026
Linux Severity
https://github.com/rails/rails/commit/29154f1097da13d48fdb3200760b3e3da66dcb11https://github.com/rails/rails/commit/b54a4b373c6f042cab6ee2033246b1c9ecc38974https://github.com/rails/rails/commit/ec1a0e215efd27a3b3911aae6df978a80f456a49https://github.com/rails/rails/releases/tag/v7.2.3.1https://github.com/rails/rails/releases/tag/v8.0.4.1https://github.com/rails/rails/releases/tag/v8.1.2.1https://github.com/rails/rails/security/advisories/GHSA-cg4j-q9v8-6v38
2026-03-24
Published