UBUNTU-CVE-2026-78689

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Source

https://ubuntu.com/security/CVE-2026-78689

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-78689.json

JSON Data

https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-78689

Upstream

CVE-2026-78689

Published

2026-09-03T00:00:00Z

Modified

2026-09-03T22:56:14Z

Severity

8.1 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
9.2 (Critical) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Ubuntu - medium

Summary

[none]

Details

Description NGINX JavaScript (njs) has a vulnerability in the XML module's namespace prefix list parser, reachable through the xml.exclusiveC14n() method. An unauthenticated remote attacker can trigger it when an affected NGINX configuration passes an externally controlled XML namespace prefix list to that method. Both the njs and the QuickJS (qjs) engines are affected. A crafted prefix list causes an out-of-bounds write past the end of a heap allocation. With the njs engine, which is the engine used when the js_engine directive is absent, this corrupts adjacent objects and crashes the NGINX worker. With the QuickJS engine, the same call additionally leaks the prefix list on every invocation, causing worker memory to grow across requests. The official nginxinc/nginx-saml reference implementation is affected during SAML signature verification. It reads InclusiveNamespaces/@PrefixList from an untrusted SAML message and passes it to xml.exclusiveC14n() before the signature has been verified, so a valid SAML signature is not required. A crafted SAML Response, Assertion, LogoutRequest, or LogoutResponse is sufficient. Code execution has not been demonstrated and cannot be ruled out for all platforms, as the effect of the out-of-bounds write depends on conditions beyond the attacker's control. Impact This vulnerability allows remote attackers to cause a denial of service on the NGINX system, either through repeatable worker restarts or through worker memory growth or possibly trigger code execution. There is no control plane exposure; this is a data plane issue only. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

References

Affected packages

Ubuntu:24.04:LTS / libnginx-mod-js

Package

Name: libnginx-mod-js
Purl: pkg:deb/ubuntu/libnginx-mod-js?arch=source&distro=noble

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

0.*

0.7.12-2

0.8.2-1ubuntu1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libnginx-mod-http-js",
            "binary_version": "0.8.2-1ubuntu1"
        },
        {
            "binary_name": "libnginx-mod-stream-js",
            "binary_version": "0.8.2-1ubuntu1"
        },
        {
            "binary_name": "njs",
            "binary_version": "0.8.2-1ubuntu1"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-78689.json"

Ubuntu:Pro:26.04:LTS / libnginx-mod-js

Package

Name: libnginx-mod-js
Purl: pkg:deb/ubuntu/libnginx-mod-js?arch=source&distro=esm-apps%2Fresolute

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

0.*

0.9.1-1ubuntu2

0.9.1-1ubuntu3

0.9.4-1~build1

0.9.4-1

0.9.4-1build1

0.9.4-1build2

0.9.4-1ubuntu0.1~esm1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libnginx-mod-http-js",
            "binary_version": "0.9.4-1ubuntu0.1~esm1"
        },
        {
            "binary_name": "libnginx-mod-stream-js",
            "binary_version": "0.9.4-1ubuntu0.1~esm1"
        },
        {
            "binary_name": "njs",
            "binary_version": "0.9.4-1ubuntu0.1~esm1"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-78689.json"