⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● Medium · CVSS 5.3

How to Fix CVE-2026-0822: Path Traversal in quickjs

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

*By Sai Kiran Pandrala*

⚡ At a glance
SeverityCVSS 5.3 - Medium
Actively exploited?Not currently listed in CISA KEV
Affected0.1, 0.2, 0.3, 0.4, 0.5, 0.6, and others
Fixed inSee vendor advisory
Type (CWE)CWE-122: Heap-based Buffer Overflow

What is CVE-2026-0822?

CVE-2026-0822 is a path traversal flaw in quickjs. The product fails to canonicalize or restrict file paths supplied by a remote caller, so .. sequences or absolute paths reach restricted parts of the filesystem. Vendor description: A vulnerability was identified in quickjs-ng quickjs up to 0.11.0. This issue affects the function js_typed_array_sort of the file quickjs.c.

Why this CVE matters

Path traversal flaws look low-impact on paper but routinely chain into full compromise. An attacker who can read arbitrary files often pulls configuration secrets, session databases, or private keys, and many traversal bugs also allow writes that drop a webshell into the document root.

For deployments of quickjs 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?

You are affected if your installation matches any of these version ranges:

Check your installed version against the list above. If you cannot determine the version, treat the system as affected and follow the upgrade path below.

Open quickjs'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-2026-0822

The fix is to apply the patched build listed in the quickjs-ng advisory.

Affected versions confirmed in the CVE record:

Patch via the OS package manager (Linux)


<!-- enrich_agent_2:v1 -->
# 1. Update the package metadata.
sudo apt update                                  # Debian / Ubuntu
sudo dnf check-update                            # RHEL / Rocky / AlmaLinux / Fedora
sudo zypper refresh                              # openSUSE

# 2. Pull the patched version listed in the [vendor advisory](https://github.com/quickjs-ng/quickjs/commit/53eefbcd695165a3bd8c584813b472cb4a69fbf5) of quickjs from quickjs-ng.
sudo apt install --only-upgrade quickjs
sudo dnf upgrade quickjs
sudo zypper update quickjs

# 3. Restart the affected service so the patched binary is the running binary.
sudo systemctl restart quickjs || true

# 4. Verify the running version.
quickjs --version

Verify the fix worked


<!-- enrich_agent_2:v1 -->
# 1. Confirm the running version matches the fixed-in version from the advisory.
#    Cross-check against the vendor advisory: https://github.com/quickjs-ng/quickjs/commit/53eefbcd695165a3bd8c584813b472cb4a69fbf5

# 2. Re-scan with your vulnerability scanner. The scanner should no longer flag
#    this CVE on the patched host.
# Example with Nmap NSE:
nmap -sV --script vuln <target-host>

# 3. Inspect the service / kernel logs for crash-loops or rollback events in
#    the first hour after the upgrade.
journalctl -u <service-name> --since "1 hour ago"
dmesg --since "1 hour ago"

If you cannot patch immediately

Block requests containing ../, ..%2f, or absolute path prefixes at a reverse proxy. Restrict access to the affected endpoint to trusted networks. Apply the patched build as the real fix.

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 unusually long URI paths containing traversal sequences, unexpectedly large responses from the affected endpoint, and outbound requests from the application to internal addresses or cloud-metadata endpoints. Treat any sensitive file the bug could disclose as exposed.

Frequently asked questions

Is CVE-2026-0822 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-2026-0822?

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.

How long should I plan for the upgrade?

Typical vendor-documented upgrade windows for quickjs run from a few minutes to under an hour depending on cluster size. Test in a staging environment first and follow the vendor's documented HA upgrade order.

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.*