Twisted up to 26.9.x Telnet Subnegotiation Buffer twisted.conch.telnet twisted.conch.telnet.Telnet.dataReceived memory allocation

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k1.64

Summaryinfo

A vulnerability was found in Twisted up to 26.9.x. It has been rated as problematic. This affects the function twisted.conch.telnet.Telnet.dataReceived of the file twisted.conch.telnet of the component Telnet Subnegotiation Buffer. Performing a manipulation results in memory allocation. This vulnerability is reported as CVE-2026-115778. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Twisted up to 26.9.x. This affects the function twisted.conch.telnet.Telnet.dataReceived of the file twisted.conch.telnet of the component Telnet Subnegotiation Buffer. The manipulation with an unknown input leads to a memory allocation vulnerability. CWE is classifying the issue as CWE-789. The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. This is going to have an impact on availability. The summary by CVE is:

Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, twisted.conch.telnet.Telnet.dataReceived appends every byte received after IAC SB to a persistent subnegotiation buffer until IAC SE is received, without applying a maximum length. Telnet option negotiation occurs before authentication, so an unauthenticated peer can omit the terminator and continuously grow the buffer. The resulting memory exhaustion can terminate the process and every service it hosts. This issue is fixed in version 26.10.0rc1.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-115778 since 10/23/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 26.10.0rc1 eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory allocation
CWE: CWE-789 / CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Twisted 26.10.0rc1

Timelineinfo

10/23/2026 Advisory disclosed
10/23/2026 +0 days CVE reserved
10/23/2026 +0 days VulDB entry created
10/23/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-115778 (🔒)
GCVE (CVE): GCVE-0-2026-115778
GCVE (VulDB): GCVE-100-426027

Entryinfo

Created: 10/23/2026 22:43
Changes: 10/23/2026 22:43 (65)
Complete: 🔍
Cache ID: 216::103

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