CVE-2026-126352: Addressable · Regular Expression Denial of Service in templates with multiple variables
Affects mikutterSource GCVE Database
Not known to be exploited · CVSS 5.9 Medium : upgrade to 5.0.5 when convenient.
Data as of 13 Nov 2026, 20:04 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 5.9 |
|---|
- Patch
- Available – fixed in 5.0.5
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 12 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 13 Nov 2026.
What to do
Upgrade mikutter to 5.0.5.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewmikutterpkg:brew/mikutterOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in Addressable version 2.9.1. Users should upgrade to this version to remediate the vulnerability. Additionally, upgrading Ruby runtimes to MRI Ruby 3.3 or later mitigates the issue due to regex memoization improvements. If upgrading is not immediately possible, avoid matching user-supplied input against templates with multiple variables in one expression or adjacent expressions, or apply short timeouts around calls to Template#match or Template#extract that process untrusted data.
Description
Addressable versions from 2.3.0 (earliest installable 2.3.2) through 2.9.0 contain a Regular Expression Denial of Service (ReDoS) vulnerability in URI template matching. Templates with multiple variables in one expression or several adjacent expressions generate regular expressions vulnerable to excessive backtracking, causing high CPU usage and denial of service when matching crafted URIs. The issue affects Ruby implementations with backtracking regex engines such as MRI Ruby < 3.3, JRuby, and TruffleRuby 40.0. The vulnerability is fixed in Addressable 2.9.1 and mitigated in MRI Ruby 3.3 and later.
References
- github.com/sporkmonger/addressable/security/advisories/GHSA-9f42-57jx-vpp3 (opens in a new tab)
- github.com/sporkmonger/addressable/commit/f2b27b3ab252e56b3fa3519f7ebb491d54cf7b7c (opens in a new tab)
- github.com/rubysec/ruby-advisory-db/blob/master/gems/addressable/GHSA-9f42-57jx-vpp3.yml (opens in a new tab)
- github.com/sporkmonger/addressable (opens in a new tab)
- github.com/sporkmonger/addressable/releases/tag/addressable-2.9.1 (opens in a new tab)