CVE-2026-105770 (GCVE-0-2026-105770)

Vulnerability from cvelistv5 – Published: 2026-11-03 00:41 – Updated: 2026-11-03 00:41
VLAI
Title
Octo STS discloses trust policy contents to unauthorized callers via Exchange error messages
Summary
Octo STS (github.com/octo-sts/app) before 0.11.2 returns trust policy configuration to callers whose OIDC token does not satisfy that policy. TrustPolicy.CheckToken included the policy's issuer, subject and audience values or patterns and claim_pattern names and regular expressions in its PermissionDenied errors, which Exchange returned verbatim. Exchange also selected the GitHub App installation before checking the token, so errors from resolving the policy's app or app_pattern pin were returned to callers the policy does not trust. An attacker who holds any validly signed OIDC token, such as a GitHub Actions token from a repository they own, and who knows or guesses a target owner/repo and identity name can read that policy's matching rules, even when the policy is stored in a private repository. These rules often name internal repositories, branches, environments or cloud account identifiers. The issue does not allow minting tokens or bypassing a trust policy. This issue is fixed in 0.11.2.
Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CWE
  • CWE-209 - Generation of Error Message Containing Sensitive Information
Assigner
chainguard CNA under the icscert root
CNA scorecard – unranked: 5 records in the last 180 days, 10 needed details
References
Impacted products
Vendor Product Version CPE status
octo-sts app Affected: 0 , < 0.11.2 (semver)
guessed Create a notification for this product.
Date Public
2026-10-06 19:34
Credits
Utkarsh Baghel (hackerrexx)
Show details on NVD website
To clipboard 

{
  "containers": {
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      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "github.com/octo-sts/app",
          "product": "app",
          "programFiles": [
            "pkg/octosts/octosts.go",
            "pkg/octosts/trust_policy.go"
          ],
          "programRoutines": [
            {
              "name": "TrustPolicy.CheckToken"
            },
            {
              "name": "Exchange"
            }
          ],
          "repo": "https://github.com/octo-sts/app",
          "vendor": "octo-sts",
          "versions": [
            {
              "lessThan": "0.11.2",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Utkarsh Baghel (hackerrexx)"
        }
      ],
      "datePublic": "2026-10-06T19:34:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Octo STS (\u003ccode\u003egithub.com/octo-sts/app\u003c/code\u003e) before 0.11.2 returns trust policy configuration to callers whose OIDC token does not satisfy that policy. \u003ccode\u003eTrustPolicy.CheckToken\u003c/code\u003e included the policy\u0027s \u003ccode\u003eissuer\u003c/code\u003e, \u003ccode\u003esubject\u003c/code\u003e and \u003ccode\u003eaudience\u003c/code\u003e values or patterns and \u003ccode\u003eclaim_pattern\u003c/code\u003e names and regular expressions in its \u003ccode\u003ePermissionDenied\u003c/code\u003e errors, which \u003ccode\u003eExchange\u003c/code\u003e returned verbatim. \u003ccode\u003eExchange\u003c/code\u003e also selected the GitHub App installation before checking the token, so errors from resolving the policy\u0027s \u003ccode\u003eapp\u003c/code\u003e or \u003ccode\u003eapp_pattern\u003c/code\u003e pin were returned to callers the policy does not trust. An attacker who holds any validly signed OIDC token, such as a GitHub Actions token from a repository they own, and who knows or guesses a target \u003ccode\u003eowner/repo\u003c/code\u003e and identity name can read that policy\u0027s matching rules, even when the policy is stored in a private repository. These rules often name internal repositories, branches, environments or cloud account identifiers. The issue does not allow minting tokens or bypassing a trust policy. This issue is fixed in 0.11.2."
            }
          ],
          "value": "Octo STS (github.com/octo-sts/app) before 0.11.2 returns trust policy configuration to callers whose OIDC token does not satisfy that policy. TrustPolicy.CheckToken included the policy\u0027s issuer, subject and audience values or patterns and claim_pattern names and regular expressions in its PermissionDenied errors, which Exchange returned verbatim. Exchange also selected the GitHub App installation before checking the token, so errors from resolving the policy\u0027s app or app_pattern pin were returned to callers the policy does not trust. An attacker who holds any validly signed OIDC token, such as a GitHub Actions token from a repository they own, and who knows or guesses a target owner/repo and identity name can read that policy\u0027s matching rules, even when the policy is stored in a private repository. These rules often name internal repositories, branches, environments or cloud account identifiers. The issue does not allow minting tokens or bypassing a trust policy. This issue is fixed in 0.11.2."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
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              "lang": "en",
              "value": "GENERAL"
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      "problemTypes": [
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          "descriptions": [
            {
              "cweId": "CWE-209",
              "description": "CWE-209: Generation of Error Message Containing Sensitive Information",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-03T00:41:24.502Z",
        "orgId": "82cea9a6-e9e3-46fe-bdb0-3673de380178",
        "shortName": "chainguard"
      },
      "references": [
        {
          "name": "GHSA-h5p6-j8m9-xx4p",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/octo-sts/app/security/advisories/GHSA-h5p6-j8m9-xx4p"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/octo-sts/app/commit/88c6432adc4f497ec69b574e1ce162a564a9e71a"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://github.com/octo-sts/app/releases/tag/v0.11.2"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eUpgrade to Octo STS 0.11.2 or later. The token is now checked against the trust policy immediately after the policy is loaded and before installation selection or app pin resolution. On a mismatch the detailed reason is logged and recorded on the operator audit event, and the caller receives only a generic \u0026quot;PermissionDenied: token does not match trust policy\u0026quot;. Policies that exist but cannot be read, parsed or compiled now return the same NotFound response as a missing policy. Users of the hosted service are protected once the fix is deployed.\u003c/p\u003e"
            }
          ],
          "value": "Upgrade to Octo STS 0.11.2 or later. The token is now checked against the trust policy immediately after the policy is loaded and before installation selection or app pin resolution. On a mismatch the detailed reason is logged and recorded on the operator audit event, and the caller receives only a generic \"PermissionDenied: token does not match trust policy\". Policies that exist but cannot be read, parsed or compiled now return the same NotFound response as a missing policy. Users of the hosted service are protected once the fix is deployed."
        }
      ],
      "source": {
        "advisory": "GHSA-h5p6-j8m9-xx4p",
        "discovery": "EXTERNAL"
      },
      "title": "Octo STS discloses trust policy contents to unauthorized callers via Exchange error messages",
      "workarounds": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eNone for self-hosted deployments other than upgrading.\u003c/p\u003e"
            }
          ],
          "value": "None for self-hosted deployments other than upgrading."
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "82cea9a6-e9e3-46fe-bdb0-3673de380178",
    "assignerShortName": "chainguard",
    "cveId": "CVE-2026-105770",
    "datePublished": "2026-11-03T00:41:24.502Z",
    "dateReserved": "2026-10-05T19:21:04.930Z",
    "dateUpdated": "2026-11-03T00:41:24.502Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-105770",
      "date": "2026-11-04",
      "epss": "0.00256",
      "percentile": "0.17422"
    },
    "nvd": {
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            "affectedData": [
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                "collectionURL": "https://pkg.go.dev",
                "defaultStatus": "unaffected",
                "packageName": "github.com/octo-sts/app",
                "product": "app",
                "programFiles": [
                  "pkg/octosts/octosts.go",
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                ],
                "programRoutines": [
                  {
                    "name": "TrustPolicy.CheckToken"
                  },
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                    "name": "Exchange"
                  }
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                "vendor": "octo-sts",
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        "cveTags": [],
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            "value": "Octo STS (github.com/octo-sts/app) before 0.11.2 returns trust policy configuration to callers whose OIDC token does not satisfy that policy. TrustPolicy.CheckToken included the policy\u0027s issuer, subject and audience values or patterns and claim_pattern names and regular expressions in its PermissionDenied errors, which Exchange returned verbatim. Exchange also selected the GitHub App installation before checking the token, so errors from resolving the policy\u0027s app or app_pattern pin were returned to callers the policy does not trust. An attacker who holds any validly signed OIDC token, such as a GitHub Actions token from a repository they own, and who knows or guesses a target owner/repo and identity name can read that policy\u0027s matching rules, even when the policy is stored in a private repository. These rules often name internal repositories, branches, environments or cloud account identifiers. The issue does not allow minting tokens or bypassing a trust policy. This issue is fixed in 0.11.2."
          }
        ],
        "id": "CVE-2026-105770",
        "lastModified": "2026-11-03T16:30:49.290",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 5.3,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "LOW",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
                "version": "3.1"
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              "source": "82cea9a6-e9e3-46fe-bdb0-3673de380178",
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        "published": "2026-11-03T01:16:44.147",
        "references": [
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            "url": "https://github.com/octo-sts/app/commit/88c6432adc4f497ec69b574e1ce162a564a9e71a"
          },
          {
            "source": "82cea9a6-e9e3-46fe-bdb0-3673de380178",
            "url": "https://github.com/octo-sts/app/releases/tag/v0.11.2"
          },
          {
            "source": "82cea9a6-e9e3-46fe-bdb0-3673de380178",
            "url": "https://github.com/octo-sts/app/security/advisories/GHSA-h5p6-j8m9-xx4p"
          }
        ],
        "sourceIdentifier": "82cea9a6-e9e3-46fe-bdb0-3673de380178",
        "vulnStatus": "Deferred",
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                "lang": "en",
                "value": "CWE-209"
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            "source": "82cea9a6-e9e3-46fe-bdb0-3673de380178",
            "type": "Secondary"
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    }
  }
}



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