Skip to main content
VulnerabilityPublished Updated

CVE-2026-81868: SteeltoeOSS security-advisories · Authentication Bypass Using an Alternate Path or Channel

Affects SteeltoeOSS security-advisoriesSource CVE Database V5

0
Compare

Not known to be exploited · CVSS 6.5 Medium : upgrade to 4.3.0 when convenient.

Data as of 1 Nov 2026, 11:03 UTC

CVSS 3.1 base score
6.5Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.2% chance of exploitation in 30 days – higher than 16% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 4.3.0
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 17 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: 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 1 Nov 2026.

What to do

Upgrade security-advisories and steeltoeoss/Steeltoe to 4.3.0.

Affected software

ProductAffectedFixed in
SteeltoeOSSsecurity-advisoriesAffected
  • <4.3.0
Fixed in
  • 4.3.0
GitHubsteeltoeoss/Steeltoepkg:github/steeltoeoss/SteeltoeOther threatsAffected
  • <4.3.0
Fixed in
  • 4.3.0

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

AI-suggested

Upgrade Steeltoe.Security.Authorization.Certificate to version 4.3.0 or later, where this authentication bypass vulnerability is fixed. Until upgrading, restrict inbound requests to trusted proxy source IPs to prevent attackers from spoofing the X-Client-Cert header. No other vendor advisories indicate alternative mitigations or that the issue is already mitigated.

Description

Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. Prior to 4.3.0, Steeltoe.Security.Authorization.Certificate deployments using AddOrgAndSpacePolicies() and UseCertificateAuthorization() trust the public certificate supplied in the X-Client-Cert request header without proving possession of the corresponding private key. Common Cloud Foundry routers do not remove this header from inbound requests. When inbound requests are not restricted to a known trusted proxy source IP, an attacker who obtains the public certificate of an application instance in the target organization or space and can reach the application can spoof X-Client-Cert to bypass the SameOrg and SameSpace policies for the certificate validity period. This issue is fixed in version 4.3.0.

References

Community reviews

Loading reviews…