CVE-2026-8711

Publication date 19 May 2026

Last updated 18 June 2026

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

8.1 · High

Score breakdown

Description

NGINX JavaScript has a vulnerability when the js_fetch_proxy directive is configured with at least one client-controlled NGINX variable (for example, $http_*, $arg_*, $cookie_*) and a location invoking the ngx.fetch() operation from NGINX JavaScript. An unauthenticated attacker can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Status

Package Ubuntu Release Status
libnginx-mod-js 26.04 LTS resolute
Fixed 0.9.4-1ubuntu0.1~esm1
25.10 questing
Not affected
24.04 LTS noble
Not affected
22.04 LTS jammy Not in release

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Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
libnginx-mod-js

Severity score breakdown

CVSS version:

Base score 9.2 · Critical

Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Base score 8.1 · High

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

Other references

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