Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
The devalue npm package, versions from 1.0.0 before 5.9.3, can allocate memory in proportion to the declared length of a sparse array when the output of its uneval function is evaluated, so a very small serialized value can trigger a large allocation in a browser or other runtime. An attacker would need to supply such a value to code that evaluates uneval output, and the source says the impact in typical client use is that the browser tab may run out of memory. Upgrade to devalue 5.9.3, which is the listed fixed version.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 8.7 | High | 4.0 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | CNA (VulnCheck) |
- CISA KEV Not listed.
- EPSS 0.0034, the 28th percentile, on 13 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 13:34 UTC First seen by agentprime
- 31 Oct 2026, 13:34 UTC Confirmed by OSV
- 8 Nov 2026, 01:45 UTC Confirmed by the CVE List
- 8 Nov 2026, 02:21 UTC Confirmed by NVD