7.5

CVE-2026-88021: hashicorp consul Incorrect Regular Expression

CVSS: 7.5v3.1HighAwaiting analysis
AliasesUBUNTU-CVE-2026-88021CGA-fc5f-wfmv-8qc2CGA-r7xq-6qvm-c876
Published 10-09-2026Last modified 02-10-2026
Open JSON

Vulnerability summary

CVE-2026-88021 is a high (CVSS 7.5) Incorrect Regular Expression vulnerability in hashicorp consul. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 25.5% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.34%
0%100%
Low · +0.09 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 10-09-2026
    PublishedVulnerability first disclosed.
  2. 02-10-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.34%

Chance of exploitation in the next 30 days

Percentile

26%

Versus all other CVEs

30-day change

+0.09 pp

From 0.24% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.34%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard2 products
  • consul-1.22All versions (No fix recorded)
  • consul-fips-1.22All versions (No fix recorded)
Hashicorp2 products
Ubuntu1 product
  • consulAll versions (No fix recorded)

3 vendors · 5 products

References

3 links