CVE-2026-126350: Addressable · Regular Expression Denial of Service in templates with certain exploded expressions
Affects asciidoctorSource GCVE Database
Not known to be exploited · CVSS 5.9 Medium : upgrade to 2.0.19 when convenient.
Data as of 15 Nov 2026, 08:42 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 5.9 |
|---|
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 36% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2.0.19
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 14 Nov 2026.
What to do
Upgrade asciidoctor to 2.0.19.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewasciidoctorpkg:brew/asciidoctorOther 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
Upgrade Addressable to version 2.9.1 or later, which contains the fix. Alternatively, upgrade Ruby to MRI 3.2 or later if not using JRuby, as these versions have regex engines that mitigate the issue. Avoid matching user-supplied input against templates using the explode (*) modifier with the /, ., ;, ?, or & operators on vulnerable versions. Applying a timeout around calls to Template#match or Template#extract can also reduce risk. Users only using template expansion or URI parsing without matching are not affected and require no action.
Description
Addressable versions from 2.3.0 (excluding yanked 2.3.0 and 2.3.1) through 2.9.0 contain a Regular Expression Denial of Service (ReDoS) vulnerability in URI template matching when using the explode (*) modifier with certain operators. This causes catastrophic backtracking on malicious inputs, leading to denial of service by consuming excessive CPU time. The issue is fixed in version 2.9.1. The vulnerability affects Ruby implementations with non-memoizing regex engines such as MRI Ruby before 3.2 and JRuby, but not MRI Ruby 3.2+ or TruffleRuby 40.0. Users only using template expansion or URI parsing without matching 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)