CVE-2026-123562 json
Devalue 5.8.0 before 5.9.3 Denial of Service via stringifyAsync Unhandled Rejection
published last mo. modified 2d ago also EUVD-2026-119447 , GHSA-x5rw-q4pp-hg5g
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 28%
- public exploits
- 0
- none known
Summary
devalue (sveltejs/devalue) 5.8.0 before 5.9.3 contains an unhandled promise rejection in stringifyAsync: when serializing multiple promises, a later promise rejecting before an earlier one settles leaves an internal rejection unhandled, even if the caller catches the returned promise. An attacker able to influence the timing or failure of serialized asynchronous values can terminate the Node.js process.
Patch / fix
- npm devalue 5.9.3
- sveltejs devalue 5.9.3
Is CVE-2026-123562 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 2d ago
Exploit prediction
0.34% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.7 | 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 | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| CNA | 4.0 | 8.7 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | devalue | >=5.8.0, <5.9.3 |
5.9.3 |
Affected products
- sveltejs devalue
Classification
References
-
github.com
/sveltejs/devalue/commit/dae8153e9d7541b975cc4018138d6cebec6c1199
web
-
github.com
/sveltejs/devalue/security/advisories/GHSA-x5rw-q4pp-hg5g
vendor-advisory, web, advisory
-
vulncheck.com
/advisories/devalue-5.8.0-before-5.9.3-denial-of-service-via-stringifyasync-unhandled-rejection
third-party-advisory
-
github.com
/sveltejs/devalue
package
-
github.com
/sveltejs/devalue/releases/tag/v5.9.3
web
Sources
- CVE List CVE-2026-123562
- GitHub Advisory GHSA-x5rw-q4pp-hg5g
- NVD CVE-2026-123562
- Maintainer advisory GHSA-x5rw-q4pp-hg5g
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
The maintainers of sveltejs/devalue published their own advisory on GitHub. Reviewed sources take precedence over it.