VulnerabilityPublished 19 Aug 2026Updated 10 Sep 2026

CVE-2026-67581: ZenHive mpp · Authentication Bypass by Capture-replay

Affects mppSource GCVE Database

Authoritative record:CVE-2026-67581· High 8.7

Not known to be exploited · CVSS 8.7 High : upgrade to 0.6.3 soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 4.0 base score

8.7High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 48% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.6.3

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: High
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 19 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-vrg5-xm7q-qcjh

What to do

Upgrade zenhive/mpp to 0.6.3.

Affected software

Product	Affected	Fixed in
GitHubzenhive/mpp`pkg:github/zenhive/mpp`Other threats	Affected <0.6.3 >=0.3.0	Fixed in 0.6.3

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

AI-suggested

If you cannot patch yet, avoid relying on transaction hash credentials alone for authentication and consider implementing additional mechanisms to bind proofs to specific challenges and prevent replay attacks.

Description

CVE-2026-67581 is an authentication bypass vulnerability in ZenHive mpp versions from 0.3.0 before 0.6.3. It allows an unauthenticated remote attacker to reuse a previously settled on-chain transfer to obtain paid resources without authorization. The vulnerability arises because the verification method accepts a transaction hash credential and matches transfers based only on token, recipient, and amount, without binding the proof to the specific challenge or preventing reuse. This enables replay attacks using publicly visible blockchain transactions.

Impact

An unauthenticated remote attacker can bypass authentication controls by replaying a previously settled on-chain transfer transaction. This allows the attacker to obtain paid resources multiple times without authorization, leading to a high impact on integrity. There is no confidentiality or availability impact reported. The CVSS 3.1 score is 7.5 (high severity) with vector AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

CWE-294Authentication Bypass by Capture-replay (opens in a new tab)
Base weaknessLikelihood of exploit: HighOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).
Architecture and Design
Utilize some sequence or time stamping functionality along with a checksum which takes this into account in order to ensure that messages can be parsed only once.
Architecture and Design
Since any attacker who can listen to traffic can see sequence numbers, it is necessary to sign messages with some kind of cryptography to ensure that sequence numbers are not simply doctored along with content.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
V9.2.3 (opens in a new tab)
Attack patterns
Session Sidejacking (opens in a new tab)
Kerberoasting (opens in a new tab)
Remote Services with Stolen Credentials (opens in a new tab)
Windows Admin Shares with Stolen Credentials (opens in a new tab)
Reusing Session IDs (aka Session Replay) (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 10 Sep 2026, 22:12 UTC

WeaknessesCWE-294

Technical details

References

Community reviews

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