8.1

CVE-2026-25793: slack nebula

CVSS: 8.1v3.1HighAnalyzed
AliasesCGA-7259-hmxh-6jgxCGA-7wr3-2jh2-8mr3CGA-9g4p-vmh9-2x8w
Published 06-02-2026Last modified 09-02-2026
Open JSON

Vulnerability summary

CVE-2026-25793 is a high (CVSS 8.1) vulnerability in slack nebula. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 7.4% of scored vulnerabilities.

Overall risk
32/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.1/10
010
High · v3.1 (NVD)
EPSS score
0.18%
0%100%
Low · +0.05 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 3
OPENSUSE-SU-2026:21483-1SUSE-SU-2026:0757-1CGA-FRWM-CMV5-PF55

Timeline

  1. 06-02-2026
    PublishedVulnerability first disclosed.
  2. 09-02-2026
    Last modifiedVulnerability information updated.

Description

Nebula is a scalable overlay networking tool. In versions from 1.7.0 to 1.10.2, when using P256 certificates (which is not the default configuration), it is possible to evade a blocklist entry created against the fingerprint of a certificate by using ECDSA Signature Malleability to use a copy of the certificate with a different fingerprint. This issue has been patched in version 1.10.3.

CVSS metrics

6 scores · 5 sources · 2 versions

EPSS trend

Probability

0.18%

Chance of exploitation in the next 30 days

Percentile

7%

Versus all other CVEs

30-day change

+0.05 pp

From 0.14% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.18%

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

Chainguard8 products
  • caddy< 2.11.0-r0
  • caddy-fips< 2.11.1-r0
  • step< 0.30.1-r0
  • step-ca< 0.30.1-r0
  • step-ca-fips< 0.30.2-r0
Wolfi4 products
  • caddy< 2.11.0-r0
  • step< 0.30.1-r0
  • step-ca< 0.30.1-r0
  • step-issuer< 0.10.1-r0
Github.com/slackhq1 product
  • nebula≥ 1.7.0, < 1.10.3
Slack1 product
Slackhq1 product

5 vendors · 15 products

References

5 links