CVE-2026-113799

Source
https://cve.org/CVERecord?id=CVE-2026-113799
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-113799.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-113799
Aliases
Published
2026-10-21T16:15:10Z
Modified
2026-10-22T02:49:07Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N CVSS Calculator
Summary
Slack Morphism verifier errors disclose valid HMACs in the logs
Details

Slack Morphism is a client library for Slack Web/Events API/Socket Mode and Block Kit. Versions 1.0.0 through 2.27.0 expose the correct Slack request HMAC when signature verification fails. For an invalid request, slack-morphism computes the correct signature for the attacker-controlled timestamp and request body and stores it in SlackEventWrongSignatureError.generated_hash. The error's Debug and Display representations expose that value, and the default Axum listener error handler logs it at error level. An attacker who can both reach the application's Slack callback endpoint and read its application/service logs can therefore use the verifier as a chosen-message HMAC oracle. The attacker can send an arbitrary request with an invalid signature, recover the correct signature from the resulting log entry, and resend the same request within the five-minute freshness window. The second request passes Slack Morphism's signature verification and reaches the protected application callback without the attacker knowing the Slack signing secret. Version 2.28.0 patches the issue.

Database specific
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-532"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/113xxx/CVE-2026-113799.json"
}
References

Affected packages

Git / github.com/abdolence/slack-morphism-rust

Affected ranges

Type
GIT
Repo
https://github.com/abdolence/slack-morphism-rust
Events
Database specific
Show details
{
    "extracted_events":  [
        {
            "range":  [
                {
                    "introduced":  "1.0.0"
                },
                {
                    "fixed":  "2.28.0"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StringRangeExpression"
        },
        {
            "range":  [
                {
                    "fixed":  "ac95d0d4539d0eac548a8db99c51c0c1ae832756"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "original_tag":  "v2.28.0",
            "range":  [
                {
                    "fixed":  "73485cdddba03ac5944276be19577c6e5e677076"
                }
            ],
            "source":  "REFERENCES_TAG"
        }
    ]
}

Affected versions

v1.*
v1.0.0
v1.1.0
v1.10.0
v1.11.0
v1.12.0
v1.14.0
v1.14.1
v1.14.2
v1.14.3
v1.14.5
v1.15.0
v1.15.1
v1.16.0
v1.16.1
v1.17.0
v1.2.0
v1.2.1
v1.2.2
v1.3.0
v1.3.1
v1.3.2
v1.3.3
v1.3.4
v1.4.0
v1.4.1
v1.4.2
v1.5.0
v1.6.0
v1.6.1
v1.7.0
v1.8.0
v1.9.0
v2.*
v2.0.0
v2.1.0
v2.10.0
v2.10.1
v2.11.0
v2.12.0
v2.14.0
v2.15.0
v2.16.0
v2.17.0
v2.18.0
v2.19.0
v2.2.0
v2.20.0
v2.21.0
v2.22.0
v2.23.0
v2.24.0
v2.24.1
v2.25.0
v2.26.0
v2.27.0
v2.3.0
v2.3.1
v2.3.2
v2.4.0
v2.4.1
v2.5.0
v2.6.0
v2.6.1
v2.6.2
v2.7.0
v2.8.0
v2.9.0

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-113799.json"