⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● Critical · CVSS 10

How to Fix CVE-2026-4745: Code Injection RCE in perf-ninja

Other vulnerabilities in the same area that are worth patching alongside this one:

*By Sai Kiran Pandrala*

⚡ At a glance
SeverityCVSS 10 - Critical
Actively exploited?Not currently listed in CISA KEV
Affectedperf-ninja - see advisory for affected version ranges
Fixed inSee vendor advisory
Type (CWE)CWE-94: Improper Control of Generation of Code ('Code Injection')

What is CVE-2026-4745?

CVE-2026-4745 is a code injection flaw in perf-ninja. Attacker-controlled input is evaluated as code by the application runtime, giving the attacker arbitrary execution inside the process. Vendor description: Improper Control of Generation of Code ('Code Injection') vulnerability in dendibakh perf-ninja (labs/misc/pgo/lua modules). This vulnerability is associated with program files ldo.C.

Why this CVE matters

Code injection against an application server is a direct path to remote code execution. The attacker executes inside the application runtime, which means database credentials, integration keys, and any secrets the process has loaded in memory are all exposed.

For deployments of perf-ninja that have been exposed to the public internet during the disclosure window, the operating assumption should be that scanning has already happened. Even where exploitation has not been publicly observed, scanning for the vulnerable fingerprint is cheap and routine. Patching closes the door; log review and credential rotation close out the rest of the response.

Am I affected?

Check your installed perf-ninja version against the affected ranges in the vendor advisory linked below. If you cannot determine the version, treat the system as potentially affected and apply the patched build.

Open perf-ninja's About dialog or run the vendor-documented version-check command. Compare the result against the affected ranges in the advisory.

How to fix CVE-2026-4745

  1. Read the vendor advisory in full: https://github.com/dendibakh/perf-ninja/pull/129
  2. Upgrade perf-ninja to the patched build listed in the vendor advisory.
  3. Back up the configuration (and database, where applicable) before upgrading.
  4. Rotate any credentials, API keys, or session tokens that the vulnerable service touched. An unauthenticated RCE-class flaw means anything the process could see should be treated as exposed.
  5. Apply the patch in a maintenance window. For HA pairs, upgrade the standby node first, fail over, then upgrade the former primary.
  6. Restart the affected service so the patched binary loads, then verify the new version (see verification section).

Open-source library upgrade

The vendor advisory (https://github.com/dendibakh/perf-ninja/pull/129) names the patched release as the build named in the vendor advisory (https://github.com/dendibakh/perf-ninja/pull/129). Pull the

fixed version through whichever ecosystem actually ships perf-ninja.


# Vendor advisory: https://github.com/dendibakh/perf-ninja/pull/129
# npm / pnpm / yarn
npm install perf-ninja@latest
npm ls perf-ninja

# Or pin to the patched version named in the advisory
npm install perf-ninja@<patched-version>

# pip / Poetry
pip install --upgrade "perf-ninja"
pip show perf-ninja | grep -i version
poetry add "perf-ninja@^<patched-version>"

# Go modules
go get example.com/perf-ninja@<patched-version>
go mod tidy

# Rust crates
cargo update -p perf-ninja

# Composer
composer require vendor/perf-ninja:^<patched-version>


# Vendor advisory: https://github.com/dendibakh/perf-ninja/pull/129
# Container image: rebuild against the patched base and roll the deployment.
docker pull <your-registry>/perf-ninja:<patched-tag>
docker stop <app> && docker rm <app>
docker run -d --name <app> <your-registry>/perf-ninja:<patched-tag>

# Kubernetes
kubectl set image deployment/<deployment-name> <container>=<your-registry>/perf-ninja:<patched-tag>
kubectl rollout status deployment/<deployment-name>

Linux package upgrade

The vendor advisory (https://github.com/dendibakh/perf-ninja/pull/129) names the patched build as the build named in the vendor advisory (https://github.com/dendibakh/perf-ninja/pull/129).


# Ubuntu / Debian
sudo apt-get update
sudo apt-get install --only-upgrade perf-ninja
dpkg -s perf-ninja | grep -i version

# RHEL / Rocky / AlmaLinux / Fedora
sudo dnf upgrade --refresh perf-ninja -y
rpm -q perf-ninja

# openSUSE
sudo zypper refresh && sudo zypper update perf-ninja

# Restart the service that loads the patched binary
sudo systemctl restart perf-ninja 2>/dev/null || true
sudo systemctl status perf-ninja --no-pager 2>/dev/null || true


# Vendor advisory: https://github.com/dendibakh/perf-ninja/pull/129
# Container deployments: rebuild with the patched package layer, then roll the workload.
docker pull <your-registry>/perf-ninja:<patched-tag>
docker stop <app> && docker rm <app>
docker run -d --name <app> <your-registry>/perf-ninja:<patched-tag>

# Kubernetes
kubectl set image deployment/<deployment-name> perf-ninja=<your-registry>/perf-ninja:<patched-tag>
kubectl rollout status deployment/<deployment-name>

Verify the fix landed


# Vendor advisory: https://github.com/dendibakh/perf-ninja/pull/129
# 1. Compare the running version against the fixed build named above.
#    (Replace the version probe with the platform-specific command from the block above.)

# 2. Re-scan with your vulnerability scanner (Nessus, Qualys, Tenable, OpenVAS).
#    The scanner should no longer flag this CVE on the patched target.

# 3. Inspect recent service / kernel logs for crash loops or rollback events.
journalctl -u <service> --since "10 minutes ago"
dmesg --since "10 minutes ago"

If you cannot patch immediately

No official workaround exists beyond restricting network exposure to the affected component. Apply the vendor patch as the primary remediation.

How to verify the fix worked

If your installation was internet-reachable during the disclosure window, treat log review as part of the remediation rather than an optional follow-up. Look for unexpected administrator accounts in perf-ninja, scheduled tasks or cron jobs you did not create, new files in web-accessible directories, and outbound connections to addresses not in your baseline. Suspicious requests to the vulnerable endpoint immediately followed by successful 200-class responses with unusually large bodies are a strong indicator of exploitation.

Frequently asked questions

Is CVE-2026-4745 being exploited in the wild?

Public exploitation has not been confirmed by CISA at the time of writing. Treat the patch as time-sensitive anyway; reports often lag actual abuse.

Will a WAF or IDS rule fully mitigate CVE-2026-4745?

No. Network-layer filters can reduce noise and slow opportunistic scanners, but they will not stop a determined attacker. The vendor patch is the only durable fix.

Do I need to assume compromise if my perf-ninja was internet-facing and unpatched?

For an unauthenticated RCE-class flaw exposed to the public internet during the known exploitation window, yes. Review logs, rotate credentials the process could access, and look for unexpected accounts, scheduled tasks, or outbound connections.

References

*This guide was assembled from the official vendor advisory, the NVD record, and the CISA KEV catalog entry on 2026-05-25. Always confirm against the vendor advisory before applying changes in production.*