IT SBIT Services
Schneeberger
DEEN
CVE tracker

Daptin: Denial of service via crafted Accept-Language header

CVE-2026-62160High 8.7

← All vulnerabilities

Summary

Daptin, an open-source GraphQL/JSON-API headless CMS, is affected by a flaw in its Accept-Language header handling. The length guard for CVE-2022-32149 counts hyphens but not underscores, so a crafted header with many underscore-separated subtags causes quadratic parsing work. An unauthenticated attacker can send such requests to the public landing page or /api and drive server CPU usage up, potentially making the service unresponsive. No confidentiality or integrity impact is documented.

Affected

  • Daptin versions below 0.12.26 (CNA record: < 0.12.26)
  • The GitHub advisory lists <= 0.12.15; whether 0.12.16 to 0.12.25 are affected is unconfirmed, so treat all versions below 0.12.26 as vulnerable

Fixed in

  • Version 0.12.26 (per CNA record)
  • Fix commit 2d70950979b51eb6c8b4234dd50558b608ad2ffe, titled "Harden Accept-Language parsing"

Workaround

  • Unknown. No vendor workaround is documented.
  • If patching is delayed, place a reverse proxy in front of Daptin that limits request header size (general measure, not vendor guidance).

Exploitation

  • Public proof of concept: yes, a single-line reproducer is included in the GitHub advisory (not verified here).
  • CISA SSVC: exploitation status 'poc', automatable: yes.
  • Exploited in the wild: no evidence found; not in CISA KEV.

Our recommendation

  • Check whether Daptin is in use and reachable from the internet.
  • Upgrade to version 0.12.26 or later promptly.
  • Until patched, limit request header size at a reverse proxy and monitor for unusual CPU load.
  • Verify the installed version after the update.

Public exploits

PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.

Research sources

Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 23:21.

Original description (NVD)

Daptin is a GraphQL/JSON-API headless CMS. Prior to 0.12.26, the global `LanguageMiddleware` in `server/language.go` passes the raw `Accept-Language` header from `LanguageMiddlewareFunc` through `GetLanguagePreference` to `golang.org/x/text/language.ParseAcceptLanguage` without a size or shape filter. The guard for CVE-2022-32149 counts hyphens but not underscores, even though the internal parser normalizes underscores to hyphens. Long lists of underscore-separated language subtags longer than eight characters bypass the guard. These subtags fail the `len <= 8` length check in `golang.org/x/text/internal/language/parse.go`, causing repeated `gobble` operations to move the entire remaining buffer through `runtime.memmove`. With many invalid subtags, this repeated buffer movement takes quadratic work. Unauthenticated requests to the public landing page or `/api` can consume disproportionate CPU, with a 256 KiB header already causing seconds of processing and larger input permitted by the default 1 MiB header ceiling. `resource.CheckErr` also logs the entire invalid header, amplifying cost, while normal successful HTTP responses can conceal the denial-of-service traffic. Repeated requests can saturate server CPU. This issue is fixed in version 0.12.26.

NVD references (3)

Sources

The tracker combines official, freely usable data sources – updated continuously:

This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.

Affected? We can help.

We check whether your systems are affected, install updates and close the gap – continuously with the System Health Checker if you wish.

Get in touchRSS feed