Security Digest · Vulnerability record
CVE-2026-22863: Deno node:crypto doesn't finalize cipher
Deno is a JavaScript, TypeScript, and WebAssembly runtime.
CVSS 9.2 Critical EPSS 0.2% · p10
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.2%, percentile 10: FIRST’s model estimates a 0.2% chance of exploitation activity in the next 30 days, higher than 10% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes
deno(crates.io (Rust)) <= 2.5.6, fixed in 2.6.0. Check your lockfile, including transitive dependencies.
What it is
Deno is a JavaScript, TypeScript, and WebAssembly runtime. Before 2.6.0, node:crypto doesn't finalize cipher. The vulnerability allows an attacker to have infinite encryptions. This can lead to naive attempts at brute forcing, as well as more refined attacks with the goal to learn the server secrets. This vulnerability is fixed in 2.6.0.
From the GitHub advisory
Summary
The vulnerability allows an attacker to have infinite encryptions.
This can lead to naive attempts at brute forcing, as well as more refined attacks with the goal to learn the server secrets.
PoC
Expected Output
Weakness type: CWE-325.
Product: deno (crates.io (Rust)) · Assigned by: GitHub_M · Published: 2026-01-15
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| crates.io (Rust) | deno | <= 2.5.6 | 2.6.0 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| denoland | deno | < 2.6.0 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 4.0 | 9.2 Critical | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N |
| GitHub | 4.0 | 9.2 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Attack requirements: none
- Privileges required: none (no login)
- User interaction: none
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none, automatable yes, technical impact partial.
- FIRST EPSS (model of 2026-10-21): 0.20% probability of exploitation activity in the next 30 days; percentile 10.
Timeline
- — CVE record published by GitHub_M
- — CVE record last updated
- — GitHub-reviewed advisory GHSA-5379-f5hf-w38v published (critical)
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-5379-f5hf-w38v github.com
- CVE.org record CVE-2026-22863 cve.org
- NVD entry CVE-2026-22863 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com
- github.com github.com
Critical crates.io (Rust) advisories · Today’s Security Digest