CVE-2026-9312Network attack vector

Unauthenticated internal service access through upload path traversal

Published May 27, 2026 · Updated May 27, 2026

SSRF in affected GitHub Enterprise Server 3.16 through 3.21 releases allows remote attackers to access internal services through an upload endpoint. The upload endpoint accepted path-traversal content in request parameters and used it to redirect internal API calls without sufficient validation. Network access to the instance is required, but authentication is not; successful requests expose internal services and sensitive credentials.

CVSS severity8.2
High
EPSS probability6.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in affected GitHub Enterprise Server 3.16 through 3.21 releases allows remote attackers to access internal services through an upload endpoint. The upload endpoint accepted path-traversal content in request parameters and used it to redirect internal API calls without sufficient validation. Network access to the instance is required, but authentication is not; successful requests expose internal services and sensitive credentials.

The record

CVE
CVE-2026-9312
Published
May 27, 2026
Updated
May 27, 2026
Vendor
Twitter
Product
GitHub Enterprise Server
Classifications
CWE-918, CAPEC-664, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 2026Record 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=3.16.0 <=3.16.19 changes=[{"at":"3.16.20","status":"unaffected"}]
  2. Affected versionversion=3.17.0 <=3.17.16 changes=[{"at":"3.17.17","status":"unaffected"}]
  3. Affected versionversion=3.18.0 <=3.18.10 changes=[{"at":"3.18.11","status":"unaffected"}]
  4. Affected versionversion=3.19.0 <=3.19.7 changes=[{"at":"3.19.8","status":"unaffected"}]
  5. Affected versionversion=3.20.0 <=3.20.3 changes=[{"at":"3.20.4","status":"unaffected"}]
  6. Affected versionversion=3.21.0 <3.21.1 changes=[{"at":"3.21.1","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Twitter · GitHub Enterprise Serverversion=3.16.0 <=3.16.19 changes=[{"at":"3.16.20","status":"unaffected"}]; version=3.17.0 <=3.17.16 changes=[{"at":"3.17.17","status":"unaffected"}]; version=3.18.0 <=3.18.10 changes=[{"at":"3.18.11","status":"unaffected"}]; version=3.19.0 <=3.19.7 changes=[{"at":"3.19.8","status":"unaffected"}]; version=3.20.0 <=3.20.3 changes=[{"at":"3.20.4","status":"unaffected"}]; version=3.21.0 <3.21.1 changes=[{"at":"3.21.1","status":"unaffected"}]

Published CVSS scores

8.2NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
9.2GitHubCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
CAPEC-664Server Side Request Forgery
T1190Exploit Public-Facing Application

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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