Daptin: ParseAcceptLanguage _ separator bypass enables >250x CPU amplification via Accept-Language header in LanguageMiddleware

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-62160: 0.42% estimated exploitation activity in the next 30 days; percentile 36.11 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Daptin's `LanguageMiddleware` (registered as a global gin middleware) calls `golang.org/x/text/language.ParseAcceptLanguage` on the raw `Accept-Language` header of every HTTP request 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 (only 256 KiB, not even the 1 MiB ceiling) consumes about 27 seconds of server CPU on the host running Daptin. A 1 MiB payload exceeds the 2-minute test client timeout. A single attacker on a 1 Mbit/s uplink can pin an entire Daptin host with one request every 30 seconds.

Affected versions `github.com/daptin/daptin` v0.12.15 and…

Published by the source

29 Oct 2026, 16:33 UTC

Last modified by the source

29 Oct 2026, 16:45 UTC

Source last checked

30 Oct 2026, 07:05 UTC

1. Revision 2 · amended · 30 Oct 2026

   Amended from osv record GHSA-rhj7-vh3v-mcq6

2. Revision 1 · created · 29 Oct 2026

   Published from ghsa record GHSA-rhj7-vh3v-mcq6

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# Patch Next advisory brief: CVE-2026-62160

Advisory: Daptin: ParseAcceptLanguage `_` separator bypass enables >250x CPU amplification via Accept-Language header in LanguageMiddleware
IDs: CVE-2026-62160, GHSA-rhj7-vh3v-mcq6
Record: https://patchnext.com/advisories/cve-2026-62160 (revision 2, source checked 30 Oct 2026, 07:05 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/daptin/daptin: affected <= 0.12.15

## Suggested inspection (read-only)
- Go github.com/daptin/daptin: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/daptin/daptin.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-rhj7-vh3v-mcq6 (GitHub-reviewed advisory GHSA-rhj7-vh3v-mcq6 lists affected ranges: Go github.com/daptin/daptin >=0 <=0.12.15)
- Verified: https://osv.dev/vulnerability/GHSA-rhj7-vh3v-mcq6 (OSV record GHSA-rhj7-vh3v-mcq6 lists affected ranges: Go github.com/daptin/daptin >=0 <=0.12.15)

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