> CVE-2026-77528 [MEDIUM]

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PUBLISHED
2026-09-18 20:17
MODIFIED
2026-09-18 20:17
CVSS_SCORE V3
5.3
EPSS (Prob. Exploit)
0.52%
Top 56.9%
DATA SOURCES:
NVD đź”— 2026-09-18 CWE MITRE đź”— 2026-10-01 FIRST EPSS đź”— 2026-10-18 GITHUB đź”— 2026-10-08 OSV đź”— 2026-10-19

> DESCRIPTION

Autobahn Python is a WebSocket and WAMP implementation for Python that supports Twisted and asyncio. Prior to 26.7.1, WebSocket endpoints that accept permessage-deflate and rely on maxMessagePayloadSize enforce that limit against the compressed frame length before inflation but do not recheck the decompressed message size before delivery. A remote unauthenticated client can send a valid compressed frame below the configured wire-size limit that expands beyond the application message limit, causing oversized data to be allocated, joined, validated, and passed to application callbacks. This can create resource-exhaustion pressure, but the advisory does not establish confidentiality or integrity impact. This issue is fixed in version 26.7.1.

> AFFECTED_PRODUCTS

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

> CVSS V3 METRICS

CVSS_VECTOR
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EXPLOITABILITY
3.9
IMPACT
1.4

> MÉTRIQUES CVSS DÉTAILLÉES

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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
None (N)
Aucune interaction utilisateur nécessaire
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
None (N)
Aucune modification de données possible
A (Impact Disponibilité)
Availability Impact
Low (L)
Interruption partielle du service possible

> RÉSUMÉ DES IMPACTS

Confidentialité
None
Aucune divulgation d'informations
Intégrité
None
Aucune modification de données possible
Disponibilité
Low
Interruption partielle du service possible

> WEAKNESSES

CWE-409 CWE-770

> CWE DETAILED DESCRIPTIONS

CWE-409: Improper Handling of Highly Compressed Data (Data Amplification) - The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output. | CWE-770: Allocation of Resources Without Limits or Throttling - The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

> GITHUB SECURITY ADVISORY

GHSA-hxp9-w8x3-p566 MODERATE

Autobahn Python permessage-deflate bypasses maxMessagePayloadSize after inflation

AFFECTED PACKAGES:
PIP / crossbar
< 26.7.1
Fixed in: 26.7.1
PIP / autobahn
< 26.7.1
Fixed in: 26.7.1

> OSV (GOOGLE OPEN SOURCE VULNERABILITIES)

Autobahn Python permessage-deflate bypasses maxMessagePayloadSize after inflation

AFFECTED PACKAGES:
Unknown / Unknown
324 versions affected
ALIASES:
GHSA-hxp9-w8x3-p566, PYSEC-2026-4027, PYSEC-2026-4031

> HISTORIQUE DES MODIFICATIONS

Première apparition
18/09/2026 20:17
Source: NVD
📊 ENRICHISSEMENT 01/10/2026 06:01
CWE
Champ modifié: Description CWE
Ancienne valeur:
N/A
Nouvelle valeur:
CWE-409: Improper Handling of Highly Compressed Data (Data Amplification) - The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a lar...
Total des modifications: 1 Dernière mise à jour: 3 weeks ago

> REFERENCES

https://github.com/crossbario/autobahn-python/commit/77d323a30b09b1828ad8be2ce63...
https://github.com/crossbario/autobahn-python/pull/1916
https://github.com/crossbario/autobahn-python/releases/tag/v26_7_1
https://github.com/crossbario/autobahn-python/security/advisories/GHSA-hxp9-w8x3...
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