Twisted up to 26.9.x HTTP Channel twisted.web.http twisted.web.http.HTTPChannel.headerReceived crlf injection

CVSS Meta Temp Score
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CTI Interest Score
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6.2$0-$5k1.62

Summaryinfo

A vulnerability was found in Twisted up to 26.9.x and classified as critical. Impacted is the function twisted.web.http.HTTPChannel.headerReceived of the file twisted.web.http of the component HTTP Channel. The manipulation results in crlf injection. This vulnerability is cataloged as CVE-2026-115877. The attack may be launched remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Twisted up to 26.9.x. Affected is the function twisted.web.http.HTTPChannel.headerReceived of the file twisted.web.http of the component HTTP Channel. The manipulation with an unknown input leads to a crlf injection vulnerability. CWE is classifying the issue as CWE-93. The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, twisted.web.http.HTTPChannel.headerReceived rejects a NUL byte in an HTTP header value but accepts a bare carriage return or bare line feed. Because Twisted splits header lines only on CRLF, a hidden Content-Length header can remain folded into another value while a lenient front end treats the bare character as a line terminator. The resulting framing disagreement can smuggle a following request past front-end access controls, poison a shared connection or cache, and expose a later client to the wrong response. This issue is an incomplete-fix residual of earlier Twisted request-smuggling protections. This issue is fixed in version 26.10.0rc1.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-115877 since 10/23/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available.

Upgrading to version 26.10.0rc1 eliminates this vulnerability.

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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: 6.2

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.4
CNA Vector (GitHub_M): 🔒

CVSSv2info

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

Exploitinginfo

Class: Crlf injection
CWE: CWE-93 / CWE-74 / CWE-707
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-2026-115877 (🔒)
GCVE (CVE): GCVE-0-2026-115877
GCVE (VulDB): GCVE-100-426024

Entryinfo

Created: 10/23/2026 22:42
Changes: 10/23/2026 22:42 (65)
Complete: 🔍
Cache ID: 216::103

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