PatchTheCVECVE-2026-56850: A flaw in Node.js HTTPS Agent connection reuse can cause PFX object-array key collisions, allowing mutual TLS
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Routine
MEDIUM 4.4UPGRADE
CVE-2026-56850 is a medium-severity flaw (CVSS 4.4) affecting node.js. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
A flaw in Node.js HTTPS Agent connection reuse can cause PFX object-array key collisions, allowing mutual TLS (mTLS) client identities to be reused across requests configured with different client certificates. This vulnerability affects Node.js **26.x**, **24.x**, and **22.x**.
Why this priority
- No elevated risk signals yet
A fixed release or distro patch exists.
Risk facts
| CVSS score | 4.4 (Medium) |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges needed | High |
| User interaction | None |
| EPSS exploit chance | 0.1% (top 100%) |
| CISA exploited list | No |
| Weakness | CWE-287 |
| Published | 2026-07-30 |
| Last modified | 2026-10-23 |
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
nodejs node.js UPGRADE
Affected: >= 22.0 and <= 22.23.1 · >= 24.0.0 and <= 24.18.0 · >= 26.0.0 and <= 26.5.0
Fixed in: newer than 26.5.0
Safe to downgrade to: a release before 22.0
1. Check installed version
apt-cache policy node.js || rpm -q node.js || node.js --version
2. UPGRADE to newer than 26.5.0 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade node.js
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade node.js
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
3. If no update is available yet, DOWNGRADE to a release before 22.0 (Debian / Ubuntu)
apt-cache madison node.js
sudo apt install node.js=<VERSION_BEFORE_22.0>
sudo apt-mark hold node.js
3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list node.js
sudo dnf downgrade node.js-<VERSION_BEFORE_22.0>
sudo dnf versionlock add node.js
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
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