Cyber Resilience

CVE-2023-26103

MediumPublic PoC

Published: 25 February 2023

Published
25 February 2023
Modified
11 March 2025
KEV Added
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Patch
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CVSS Score v3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS Score 0.0066 71.7th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-26103 is a medium-severity Inefficient Regular Expression Complexity (CWE-1333) vulnerability in Deno Deno. Its CVSS base score is 5.3 (Medium).

Operationally, ranked in the top 28.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

Versions of the package deno before 1.31.0 are vulnerable to Regular Expression Denial of Service (ReDoS) due to the upgradeWebSocket function, which contains regexes in the form of /s*,s*/, used for splitting the Connection/Upgrade header. A specially crafted Connection/Upgrade header…

more

can be used to significantly slow down a web socket server.

CWE(s)
CWE-1333

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

deno
deno
≤ 1.31.0

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References