Resource allocation without limits in lucasdillmann nginx-ignition
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-770.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| lucasdillmann | nginx-ignition | 2.29.0 to before 2.40.1 | 2.40.1 | Patch available | CNA |
| — | github.com/lucasdillmann/nginx-ignition (Go) | 0.0.0-20260126024607-cbaf0fc16ed8 to before 0.0.0-20260526022344-0c988fc1277c | 0.0.0-20260526022344-0c988fc1277c | Patch available | GHSA-jr34-h97m-9hpx |
- nginx-ignition Vendorlucasdillmann Affected 2.29.0 to before 2.40.1 Fixed in 2.40.1 Patch available CNA
- github.com/lucasdillmann/nginx-ignition (Go) Vendor— Affected 0.0.0-20260126024607-cbaf0fc16ed8 to before 0.0.0-20260526022344-0c988fc1277c Fixed in 0.0.0-20260526022344-0c988fc1277c Patch available GHSA-jr34-h97m-9hpx
Remediation
- Fix · CNA nginx-ignition (lucasdillmann) Fixed in 2.40.1
- Fix · GHSA-jr34-h97m-9hpx github.com/lucasdillmann/nginx-ignition (Go) Fixed in 0.0.0-20260526022344-0c988fc1277c Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-61629
- 2026-10-03 Alias added: GHSA-jr34-h97m-9hpx
References
Other 6
- https://github.com/lucasdillmann/nginx-ignition/security/advisories/GHSA-jr34-h97m-9hpx
- https://github.com/lucasdillmann/nginx-ignition/commit/0c988fc1277c7d291725e8373313f8486fa1b31a
- https://github.com/lucasdillmann/nginx-ignition/commit/cbaf0fc16ed873f7178a2ca9b0d00a696e44b485
- https://github.com/lucasdillmann/nginx-ignition/pull/125
- https://github.com/lucasdillmann/nginx-ignition
- https://github.com/lucasdillmann/nginx-ignition/releases/tag/2.40.1
More lucasdillmann vulnerabilities
- TI-2026-44137 nginx ignition has Unauthenticated Admin Account Creation via Onboarding Race Condition CVSS 3.1HIGH 8.1
- TI-2026-44139 nginx ignition has TOTP Reuse During Validity Window CVSS 3.1MEDIUM 4.2
Sources
- CVE-2026-61629 · CVE Program
- CVE-2026-61629 · NVD
- FIRST EPSS
- GHSA-jr34-h97m-9hpx · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences