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CVE-2026-88021VulnerabilityPublished Updated

CVE-2026-88021: HashiCorp Consul · Incorrect Regular Expression

Affects HashiCorp ConsulSource CVE Database V5

0

Not known to be exploited · CVSS 7.5 High : upgrade to 2.0.4 soon.

Data as of 26 Oct 2026, 08:30 UTC

CVSS 3.1 base score
7.5High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 26% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 2.0.4, 1.21.18
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 10 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 26 Oct 2026.

What to do

Upgrade Consul and Consul Enterprise to 2.0.4; Consul Enterprise to 1.21.18.

Affected software

ProductAffectedFixed in
HashiCorpConsulAffected
  • >=1.9.0 <2.0.4
Fixed in
  • 2.0.4
HashiCorpConsul EnterpriseAffected
  • >=1.9.0 <1.21.18
Fixed in
  • 2.0.4
GitHubConsulpkg:github/ConsulOther threatsAffected
  • >=1.9.0 <2.0.4
Fixed in
  • 2.0.4
GitHubConsul Enterprisepkg:github/Consul EnterpriseOther threatsAffected
  • >=1.9.0 <1.21.18
Fixed in
  • 1.21.18

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Apply the official patches provided by HashiCorp. Upgrade to Consul version 2.0.4 or later and Consul Enterprise versions 1.21.18, 1.22.12, or 2.0.4 or later to remediate this vulnerability. No alternative mitigations are indicated by the vendor advisory.

Description

Consul and Consul Enterprise are vulnerable to an authorization bypass in the Connect service mesh that may allow a service to reach a destination it is not authorized to access. When building Envoy RBAC rules to enforce Connect intentions, Consul did not correctly escape certain characters in service names, namespaces, and partitions, causing the generated authorization rules to match more broadly than intended. This vulnerability (CVE-2026-88021) is fixed in Consul 2.0.4 and Consul Enterprise 1.21.18, 1.22.12 and 2.0.4.

References

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