CVE-2026-61629

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Source
https://cve.org/CVERecord?id=CVE-2026-61629
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-61629.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-61629
Aliases
Published
2026-09-21T14:22:34Z
Modified
2026-09-22T03:45:31Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
nginx ignition has ParseAcceptLanguage `_` separator bypass that enables ~75x CPU amplification via Accept-Language header in i18nMiddleware
Details

nginx ignition is a user interface for the nginx web server. In versions 2.29.0 through 2.40.0, the gin i18n middleware in nginx-ignition's API server runs in front of every HTTP request and calls golang.org/x/text/language.ParseAcceptLanguage on the raw Accept-Language header without imposing any size or shape filter. The underlying parser has quadratic-time behaviour on long lists of malformed language tags. The CVE-2022-32149 guard that golang.org/x/text added in v0.3.8 caps the number of - characters in the input at 1000, but it does not cap _ characters even though the parser's internal scanner aliases _ to - before parsing. A single unauthenticated GET request with an Accept-Language header built out of _ separators burns about 2.4 seconds of server CPU on the host running nginx-ignition; ten concurrent attackers saturate a ten-core box for the duration of the attack while consuming ~10 MiB/s of upstream bandwidth. Version 2.40.1 fixes this issue.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-770"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61629.json"
}
References

Affected packages

Git / github.com/lucasdillmann/nginx-ignition

Affected ranges

Type
GIT
Repo
https://github.com/lucasdillmann/nginx-ignition
Events
Introduced
268a7816033a9df678538c594013af709dbf63be
Fixed
0c988fc1277c7d291725e8373313f8486fa1b31a
Database specific
Show details 
{
    "extracted_events":  [
        {
            "introduced":  "2.29.0"
        },
        {
            "fixed":  "2.40.1"
        }
    ],
    "source":  "AFFECTED_FIELD"
}

Affected versions

2.*
2.29.0
2.29.1
2.30.0
2.31.0
2.31.1
2.31.2
2.32.0
2.33.0
2.34.0
2.35.0
2.35.1
2.35.2
2.35.3
2.36.0
2.36.1
2.37.0
2.38.0
2.39.0
2.40.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-61629.json"