Skip to main content

Boteraser | Website and Server Security Solutions

🛡️ CVE-2026-42874 — microdot

🟢 CVSS 3.7 — Low ✅ No Known Exploit CWE-113 NVD
3.7
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Microdot has HTTP response splitting in Response.set_cookie()

Impact

The Response.set_cookie() method does not sanitize its string arguments, and in particular will not detect the presence of the \r\n sequence in them. This can be a potential source of header injection attacks.

For a header injection attack through this issue to be possible, an attacker must first infiltrate the client (for example through an independent XSS attack), so that it can send malicious information that is destined to be stored in a cookie by the server on behalf of the victim. An attacker that infiltrates one client can only orchestrate a header injection attack for that client, all other clients that were not infiltrated are safe.

Patches

Upgrade to version 2.6.1.

Workarounds

Do not pass untrusted data to the Response.set_cookie() method.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is high, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity low, availability none.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: High — the attacker first has to win a race, learn a secret or otherwise prepare the target.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: None.
  • Integrity impact: Low — limited, and the attacker does not choose what is affected.
  • Availability impact: None.

Weakness class

CVE-2026-42874 is classified as CWE-113: HTTP Response Splitting. Unescaped input reaches an HTTP header, letting an attacker inject line breaks and forge additional headers or responses.

Affected software

CVE-2026-42874 is recorded against 2 packages.

  • microdot (fixed in 2.6.1)
  • unknown

Timeline and source

Published on 13 July 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

github.com (Web)
nvd.nist.gov (Advisory)
github.com (Web)
github.com (Package)
github.com (Web)
pypi.org (Package)
github.com (Advisory)

Same weakness in other software

These advisories are the same class of weakness (CWE-113: HTTP Response Splitting) in other software:

Details

Severity LOW
CVSS Score 3.7
CVSS Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CWE CWE-113
Public Exploit ✅ No
Source NVD
Published 2026-07-13
Updated 2026-08-20
Modified 2026-07-13
Fix URL N/A

Affected Packages

Software From version Fixed in
microdot — 2.6.1
unknown — —

Free Vulnerability Check

Is your site affected by CVE-2026-42874?

BotEraser helps you identify potentially vulnerable plugins and themes by checking your installation against CVE-2026-42874 and other known CVE records.

Scan My Site Free →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

Browse related advisories

All advisoriesCVECVE 2026
✓