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HIGH severity

GHSA-45m3-398w-m2m9 OliveTin

HIGHFix: OliveTin/OliveTin@f044d90

GHSA-45m3-398w-m2m9 is a high-severity (CVSS 7.5) CWE-362 vulnerability in github.com/OliveTin/OliveTin. A fix is available for github.com/OliveTin/OliveTin — see the affected versions and patch details below.

OliveTin has unauthenticated DoS via concurrent map writes in OAuth2 state handling

Also known asCVE-2026-28789GO-2026-4586
Published
Mar 2, 2026
Updated
Mar 23, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 22, 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-45m3-398w-m2m9.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs33th percentile — riskier than 33% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

GHSA-45m3-398w-m2m9 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

1 pkg affected
🐹github.com/OliveTin/OliveTin

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

An unauthenticated denial-of-service vulnerability exists in OliveTin’s OAuth2 login flow. Concurrent requests to /oauth/login can trigger unsynchronized access to a shared registeredStates map, causing a Go runtime panic (fatal error: concurrent map writes) and process termination. This allows remote attackers to crash the service when OAuth2 is enabled.

Details

The OAuth2 handler stores per-login state in a shared map without synchronization:

  • service/internal/auth/otoauth2/restapi_auth_oauth2.go:24 registeredStates map[string]*oauth2State
  • Unlocked write in login handler: .../restapi_auth_oauth2.go:141
  • Unlocked read in callback check: .../restapi_auth_oauth2.go:174
  • Unlocked writes in callback flow: .../restapi_auth_oauth2.go:284-285
  • Unlocked read in auth chain check: .../restapi_auth_oauth2.go:376

These paths are network reachable via publicly registered routes:

  - service/internal/httpservers/frontend.go:71 → /oauth/login
  - service/internal/httpservers/frontend.go:72 → /oauth/callback

Because Go HTTP handlers run concurrently, high parallel traffic to /oauth/login causes concurrent map access and runtime panic.

Tested on:

  • Container image: ghcr.io/olivetin/olivetin:3000.10.0
  • Source also contains same pattern at commit/tag eb42029b5d0c0633551621288180dd4566b913f7 (3000.10.1)

PoC

  1. Start OliveTin with OAuth2 provider configured (example github), exposing port 1337.
  2. Confirm baseline:
  curl -i http://127.0.0.1:1337/readyz
  curl -i "http://127.0.0.1:1337/oauth/login?provider=github"

Expected: 200 for /readyz, 302 for /oauth/login.

  1. Run concurrency PoC:
  python3 /OliveTin/tools/poc_oauth2_state_map_race_dos.py \
    --base-url http://127.0.0.1:1337 \
    --provider github \
    --workers 80 \
    --requests 120000 \
    --health-failures 3
  1. Verify crash:

docker inspect olivetin-dos --format 'status={{.State.Status}} exit={{.State.ExitCode}}' docker logs olivetin-dos 2>&1 | grep -E "fatal error: concurrent map|concurrent map writes|restapi_auth_oauth2.go"

Observed result:

  • Process exited with code 2
  • Logs include:
    • fatal error: concurrent map writes
    • .../internal/auth/otoauth2/restapi_auth_oauth2.go:141 in HandleOAuthLogin

Impact

  • Vulnerability type: Race condition (CWE-362) leading to DoS.
    • Attacker requirements: network access only; no authentication required for exploit path.
    • Impacted deployments: OliveTin instances with OAuth2 enabled and reachable over network.
    • Security impact: remote unauthenticated attacker can repeatedly crash OliveTin, causing availability loss until restart/recovery.

poc_oauth2_state_map_race_dos.py

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/OliveTin/OliveTinall versions0.0.0-20260301235225-f044d90d5525cgo get github.com/OliveTin/OliveTin@v0.0.0-20260301235225-f044d90d5525c

Detection & mitigation playbook

Open-source dependency
  1. Detect

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

  2. Fix

    Update github.com/OliveTin/OliveTin to 0.0.0-20260301235225-f044d90d5525c or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-45m3-398w-m2m9 is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-45m3-398w-m2m9 can be triaged on real exposure rather than presence alone.

Tailored to GHSA-45m3-398w-m2m9. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary An unauthenticated denial-of-service vulnerability exists in OliveTin’s OAuth2 login flow. Concurrent requests to /oauth/login can trigger unsynchronized access to a shared registeredStates map, causing a Go runtime panic (fatal error: concurrent map writes) and process termination. This allows remote attackers to crash the service when OAuth2 is enabled. ### Details The OAuth2 handler stores per-login state in a shared map without synchronization: - service/internal/auth/otoauth2/restapi_auth_oauth2.go:24 registeredStates map[string]*oauth2State - Unlocked write in lo
O3 Security · Impact-Aware SCA

Is GHSA-45m3-398w-m2m9 in your dependencies?

O3 Security finds GHSA-45m3-398w-m2m9 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-45m3-398w-m2m9: OliveTin (High 7.5) | O3 Security