> CVE-2026-56727 [HIGH]

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PUBLISHED
2026-09-25 18:17
MODIFIED
2026-09-25 18:17
CVSS_SCORE V3
7.1
EPSS (Prob. Exploit)
0.25%
Top 85.0%
DATA SOURCES:
NVD đź”— 2026-09-25 CWE MITRE đź”— 2026-10-01 FIRST EPSS đź”— 2026-10-23 OSV đź”— 2026-09-29

> DESCRIPTION

Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.2, summary In Zammad's inbound PGP email processing, the return value of the gpg verification call was silently discarded. Regardless of whether gpg reported a valid, invalid, or missing signature, the handler unconditionally wrote sign: { success: true, comment: "Good signature" } to the article's security preferences. Impact Any sender could tamper with the body of a multipart/signed PGP email, or craft a message with an entirely fabricated or mismatched signature, and Zammad would display it to the recipient as cryptographically verified with a "Good signature" label. Users and agents relying on Zammad's signature indicator to confirm message authenticity and integrity would be misled into trusting modified or forged content. The vulnerability affects all inbound PGP-signed emails processed while the PGP integration is enabled. This issue is fixed in version 7.0.2.

> AFFECTED_PRODUCTS

ℹ️ Aucun produit affecté n'a encore été publié par NVD pour cette CVE.

> CVSS V3 METRICS

CVSS_VECTOR
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

> MÉTRIQUES CVSS DÉTAILLÉES

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Métrique Valeur Interprétation
AV (Vecteur d'Attaque)
Attack Vector
Network (N)
Exploit possible à distance via réseau (HTTP, API, etc.)
AC (Complexité d'Attaque)
Attack Complexity
Low (L)
Peu de conditions requises pour exploiter
PR (Privilèges Requis)
Privileges Required
None (N)
Aucune authentification requise
UI (Interaction Utilisateur)
User Interaction
Unknown (P)
Interaction inconnue
S (Périmètre)
Scope
Unchanged (U)
Impact reste dans le périmètre du composant compromis
C (Impact Confidentialité)
Confidentiality Impact
None (N)
Aucune divulgation d'informations
I (Impact Intégrité)
Integrity Impact
High (H)
Modification totale des données possible
A (Impact Disponibilité)
Availability Impact
None (N)
Aucune interruption de service

> RÉSUMÉ DES IMPACTS

Confidentialité
None
Aucune divulgation d'informations
Intégrité
High
Modification totale des données possible
Disponibilité
None
Aucune interruption de service

> WEAKNESSES

CWE-287 CWE-347 CWE-391

> CWE DETAILED DESCRIPTIONS

CWE-287: Improper Authentication - When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. | CWE-347: Improper Verification of Cryptographic Signature - The product does not verify, or incorrectly verifies, the cryptographic signature for data. | CWE-391: Unchecked Error Condition - [PLANNED FOR DEPRECATION. SEE MAINTENANCE NOTES AND CONSIDER CWE-252, CWE-248, OR CWE-1069.] Ignoring exceptions and other error conditions may allow an attacker to induce unexpected behavior unnoticed.

> OSV (GOOGLE OPEN SOURCE VULNERABILITIES)

Zammad: PGP signature spoofing via unvalidated verification return

AFFECTED PACKAGES:
Unknown / Unknown
16 versions affected
ALIASES:
GHSA-56jc-34c8-2xq4

> HISTORIQUE DES MODIFICATIONS

Première apparition
25/09/2026 18:17
Source: NVD
📊 ENRICHISSEMENT 01/10/2026 06:01
CWE
Champ modifié: Description CWE
Ancienne valeur:
N/A
Nouvelle valeur:
CWE-287: Improper Authentication - When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. | CWE-347: Improper Verification of Cry...
Total des modifications: 1 Dernière mise à jour: 3 weeks ago

> REFERENCES

https://github.com/zammad/zammad/commit/4a9dd5f8a85948c5a2f96f6479d785153aac05d7
https://github.com/zammad/zammad/releases/tag/7.0.2
https://github.com/zammad/zammad/security/advisories/GHSA-56jc-34c8-2xq4
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