How severe is GHSA-x6cr-mq53-cc76?

GHSA-x6cr-mq53-cc76 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-x6cr-mq53-cc76?

GHSA-x6cr-mq53-cc76 affects the following packages: emmett-core (PyPI). Ecosystems affected: PyPI.

How do I fix GHSA-x6cr-mq53-cc76?

Update emmett-core to 1.3.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x6cr-mq53-cc76 is resolved across your whole dependency graph.

How do I detect GHSA-x6cr-mq53-cc76 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for emmett-core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-x6cr-mq53-cc76 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-x6cr-mq53-cc76?

O3 pinpoints whether GHSA-x6cr-mq53-cc76 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-x6cr-mq53-cc76 actively exploited in the wild?

No public exploit code has been indexed for GHSA-x6cr-mq53-cc76 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-x6cr-mq53-cc76?

GHSA-x6cr-mq53-cc76 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 19th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-x6cr-mq53-cc76?

GHSA-x6cr-mq53-cc76 is classified as CWE-248 (CWE-248), CWE-307 (CWE-307). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-x6cr-mq53-cc76 published, and has it been updated?

GHSA-x6cr-mq53-cc76 was published on February 10, 2026 and was last updated on February 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

GHSA-x6cr-mq53-cc76

HIGH

Emmett-Core: Unhandled CookieError Exception Causing Denial of Service

Also known asCVE-2026-25577

Published

Feb 10, 2026

Updated

Feb 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk19th percentile+0.19%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

🐍emmett-core

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Summary

The cookies property in emmett_core.http.wrappers.Request does not handle CookieError exceptions when parsing malformed Cookie headers. This allows unauthenticated attackers to trigger HTTP 500 errors and cause denial of service.

Details

Location: emmett_core/http/wrappers/__init__.py (line 64)

Vulnerable Code:

@cachedprop
def cookies(self) -> SimpleCookie:
    cookies: SimpleCookie = SimpleCookie()
    for cookie in self.headers.get("cookie", "").split(";"):
        cookies.load(cookie)  # No exception handling
    return cookies

PoC

Sending cookies containing special characters such as /(){} will result in insufficient error handling and a server error.

$ curl -w "\nTime: %{time_total}s\n" http://localhost:8000/ -H "Cookie:/security=test"
Internal error
Time: 0.024363s

After the same error occurs several times, the server cannot process it normally.

$ curl -w "\nTime: %{time_total}s\n" http://localhost:8000/ -H "Cookie:(security=test"
Internal error
Time: 60.069334s

$ curl -w "\nTime: %{time_total}s\n" http://localhost:8000/ -H "Cookie:security=test"
Internal error
Time: 60.074031s

This is server log.

[2026-02-03 08:23:40,541] ERROR in handlers: Application exception:
Traceback (most recent call last):
  File "/home/geonwoo/.local/lib/python3.13/site-packages/emmett/rsgi/handlers.py", line 70, in dynamic_handler
    http = await self.router.dispatch(request, response)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/routing/router.py", line 240, in dispatch
    return await match.dispatch(reqargs, response)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/routing/dispatchers.py", line 57, in dispatch
    await self._parallel_flow(self.flow_open)
  File "/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/routing/dispatchers.py", line 17, in _parallel_flow
    raise task.exception()
  File "/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/sessions.py", line 102, in open_request
    if self.cookie_name in self.current.request.cookies:
                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/utils.py", line 37, in __get__
    obj.__dict__[self.__name__] = rv = self.fget(obj)
                                       ~~~~~~~~~^^^^^
  File "/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/http/wrappers/__init__.py", line 64, in cookies
    cookies.load(cookie)
    ~~~~~~~~~~~~^^^^^^^^
  File "/usr/lib/python3.13/http/cookies.py", line 516, in load
    self.__parse_string(rawdata)
    ~~~~~~~~~~~~~~~~~~~^^^^^^^^^
  File "/usr/lib/python3.13/http/cookies.py", line 580, in __parse_string
    self.__set(key, rval, cval)
    ~~~~~~~~~~^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/http/cookies.py", line 472, in __set
    M.set(key, real_value, coded_value)
    ~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/http/cookies.py", line 335, in set
    raise CookieError('Illegal key %r' % (key,))
http.cookies.CookieError: Illegal key '/security'

Impact

This vulnerability allows unauthenticated attackers to cause denial of service and performance degradation by sending malformed Cookie headers. After this vulnerability occurs, we expect it to be difficult to use the normal service.

patch

/emmett_core/http/wrappers/__init__.py

- from http.cookies import SimpleCookie 
+ from http.cookies import SimpleCookie, CookieError  # add CookieError
...
...
    @cachedprop
    def cookies(self) -> SimpleCookie:
        cookies: SimpleCookie = SimpleCookie()
        for cookie in self.headers.get("cookie", "").split(";"):
-           cookies.load(cookie)
+           try:
+               cookies.load(cookie)
+            except CookieError:
+                continue
        return cookies

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`emmett-core`	all versions	1.3.11

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for emmett-core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update emmett-core to 1.3.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x6cr-mq53-cc76 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-x6cr-mq53-cc76 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-x6cr-mq53-cc76. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary The `cookies` property in `emmett_core.http.wrappers.Request` does not handle `CookieError` exceptions when parsing malformed Cookie headers. This allows unauthenticated attackers to trigger HTTP 500 errors and cause denial of service. ### Details **Location:** `emmett_core/http/wrappers/__init__.py` (line 64) **Vulnerable Code:** ```python @cachedprop def cookies(self) -> SimpleCookie: cookies: SimpleCookie = SimpleCookie() for cookie in self.headers.get("cookie", "").split(";"): cookies.load(cookie) # No exception handling return cookies ``` ### PoC Se

O3 Security · Impact-Aware SCA

Is GHSA-x6cr-mq53-cc76 in your dependencies?

O3 detects GHSA-x6cr-mq53-cc76 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works