Go net http internal http2 x net http2 HTTP/2 Server Flow Control multiple operations on resource in single-operation context

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.2$0-$5k0.35

Summaryinfo

A vulnerability has been found in Go net http internal http2 x net http2 and classified as problematic. Affected by this issue is some unknown functionality of the component HTTP2 Server Flow Control. The manipulation leads to multiple operations on resource in single-operation context. This vulnerability is documented as CVE-2026-78663. The attack can be initiated remotely. There is not any exploit available. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability was found in Go net http internal http2 x net http2 (the affected version unknown). It has been rated as problematic. This issue affects an unknown part of the component HTTP2 Server Flow Control. The manipulation with an unknown input leads to a multiple operations on resource in single-operation context vulnerability. Using CWE to declare the problem leads to CWE-675. The product performs the same operation on a resource two or more times, when the operation should only be applied once. Impacted is integrity, and availability. The summary by CVE is:

The HTTP/2 server can refund connection-level flow control twice for the same data: Once when a client resets a stream (refunding data for any sent-but-unread portion of the stream), and again when a request handler reads the buffered data. A malicious client can exploit this to bypass the configured connection-level flow control limit (MaxReceiveBufferPerConnection). Total buffered data is still limited by the concurrent stream limit and stream-level flow control.

The identification of this vulnerability is CVE-2026-78663 since 08/25/2026. The exploitation is known to be easy. The attack may be initiated remotely. The technical details are unknown and an exploit is not publicly available.

Applying the patch 847187 is able to eliminate this problem.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-95427). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

Name

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.2

VulDB Base Score: 5.4
VulDB Temp Score: 5.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Multiple operations on resource in single-operation context
CWE: CWE-675
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: Patch
Status: 🔍

0-Day Time: 🔒

Patch: 847187

Timelineinfo

08/25/2026 CVE reserved
10/08/2026 +44 days VulDB entry created
10/09/2026 +0 days Advisory disclosed
10/09/2026 +0 days VulDB entry last update

Sourcesinfo

Status: Confirmed

CVE: CVE-2026-78663 (🔒)
GCVE (CVE): GCVE-0-2026-78663
GCVE (VulDB): GCVE-100-415691
EUVD: 🔒

Entryinfo

Created: 10/09/2026 01:03
Updated: 10/09/2026 02:28
Changes: 10/09/2026 01:03 (52), 10/09/2026 02:28 (1)
Complete: 🔍
Cache ID: 216::103

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

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