CVE-2023-6803

Unauthorized collaborator addition via repository-transfer race

Published Dec 21, 2023 · Updated Aug 2, 2024

Race condition in GitHub Enterprise Server allows attackers to add an outside collaborator while a repository is being transferred. The repository-transfer workflow does not keep its collaborator-eligibility check and collaborator update atomic, so concurrent state changes invalidate the checked result. Exploitation requires a repository transfer to overlap collaborator addition; GitHub has not disclosed a narrower code-level locus, and the bounded result is unauthorized collaborator membership.

CVSS severity5.8
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in GitHub Enterprise Server allows attackers to add an outside collaborator while a repository is being transferred. The repository-transfer workflow does not keep its collaborator-eligibility check and collaborator update atomic, so concurrent state changes invalidate the checked result. Exploitation requires a repository transfer to overlap collaborator addition; GitHub has not disclosed a narrower code-level locus, and the bounded result is unauthorized collaborator membership.

The record

CVE
CVE-2023-6803
Published
Dec 21, 2023
Updated
Aug 2, 2024
Vendor
Twitter
Product
GitHub Enterprise Server
Classifications
CWE-367, T1098
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 21, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.10 <=3.10.3 changes=[{"at":"3.10.4","status":"unaffected"}]
  2. Affected versionversion=3.11 <=3.11.0 changes=[{"at":"3.11.1","status":"unaffected"}]
  3. Affected versionversion=3.8 <=3.8.11 changes=[{"at":"3.8.12","status":"unaffected"}]
  4. Affected versionversion=3.9 <=3.9.6 changes=[{"at":"3.9.7","status":"unaffected"}]

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Twitter · GitHub Enterprise Serverversion=3.10 <=3.10.3 changes=[{"at":"3.10.4","status":"unaffected"}]; version=3.11 <=3.11.0 changes=[{"at":"3.11.1","status":"unaffected"}]; version=3.8 <=3.8.11 changes=[{"at":"3.8.12","status":"unaffected"}]; version=3.9 <=3.9.6 changes=[{"at":"3.9.7","status":"unaffected"}]

Published CVSS scores

4.0NIST NVDCVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:N/I:H/A:N
5.8GitHub, Inc.CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
T1098Account Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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