CVE-2026-126350: Addressable · Regular Expression Denial of Service in templates with certain exploded expressions
Affects addressableSource GCVE Database
Not known to be exploited · CVSS 5.9 Medium : upgrade to 2.9.1 when convenient.
Data as of 12 Nov 2026, 23:21 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 5.9 |
|---|
- Patch
- Available – fixed in 2.9.1
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 12 Nov 2026.
What to do
Upgrade addressable to 2.9.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| RubyGemsaddressable | 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; upgrading to this version fully remediates the vulnerability. Alternatively, upgrading to MRI Ruby 3.2 or later also mitigates the issue due to regex engine memoization. Users unable to upgrade should avoid matching user-supplied input against vulnerable templates using the explode (*) modifier with the specified operators. Applying short timeouts around calls to Template#match or Template#extract that process untrusted data can also mitigate impact.
Description
Addressable versions from 2.3.0 up to but not including 2.9.1 contain a Regular Expression Denial of Service (ReDoS) vulnerability in URI templates that use the explode (*) modifier with certain operators. This vulnerability causes catastrophic backtracking when matching maliciously crafted URIs, leading to exponential processing time and denial of service. The issue is fixed in version 2.9.1. Ruby MRI versions prior to 3.2 and JRuby are vulnerable, while MRI 3.2+ and TruffleRuby 40.0 are not affected.
References
- github.com/sporkmonger/addressable/security/advisories/GHSA-j82w-28jv-3pmj (opens in a new tab)
- github.com/sporkmonger/addressable/issues/364 (opens in a new tab)
- github.com/sporkmonger/addressable/commit/26d1e9e8409a861571f9d0029022b6e9b9158b5e (opens in a new tab)
- github.com/rubysec/ruby-advisory-db/blob/master/gems/addressable/GHSA-j82w-28jv-3pmj.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)