CVE-2026-53878 | Header injection possibility since DomainNameValidator accepted newlines in input

An issue was discovered in Django 6.0 before 6.0.7 and 5.2 before 5.2.16. `DomainNameValidator` does not prohibit newlines in domain names (unless used via a form field, since `CharField` strips newlines). If an application uses values with newlines in an HTTP response, header injection can occur. Django itself is unaffected because `HttpResponse` prohibits newlines in HTTP headers. Earlier, unsupported Django series (such as 5.0.x, 4.1.x, and 3.2.x) were not evaluated and may also be affected. Django would like to thank Bence Nagy for reporting this issue.

Published: 2026-07-07 Last update: 2026-07-09 Assigner: 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92 Source: 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-53878 is rated Low Risk (25.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.22%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-53878

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-07-08 — 0.22% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-53878

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 4.0 MEDIUM
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:P)
A user has to participate (for example click/open/approve).
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:N)
No integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:L)
Limited confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:L)
Limited integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:X)
Not defined: no reliable threat intelligence; scoring assumes the worst case (equivalent to Attacked).
Confidentiality requirement (CR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Integrity requirement (IR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Availability requirement (AR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Modified attack vector (MAV:X)
Not defined: scoring uses the Base Attack Vector (AV).
Modified attack complexity (MAC:X)
Not defined: scoring uses the Base Attack Complexity (AC).
Modified attack requirements (MAT:X)
Not defined: scoring uses the Base Attack Requirements (AT).
Modified privileges required (MPR:X)
Not defined: scoring uses the Base Privileges Required (PR).
Modified user interaction (MUI:X)
Not defined: scoring uses the Base User Interaction (UI).
Modified vulnerable system confidentiality impact (MVC:X)
Not defined: scoring uses the Base VC metric.
Modified vulnerable system integrity impact (MVI:X)
Not defined: scoring uses the Base VI metric.
Modified vulnerable system availability impact (MVA:X)
Not defined: scoring uses the Base VA metric.
Modified subsequent system confidentiality impact (MSC:X)
Not defined: scoring uses the Base SC metric.
Modified subsequent system integrity impact (MSI:X)
Not defined: scoring uses the Base SI metric.
Modified subsequent system availability impact (MSA:X)
Not defined: scoring uses the Base SA metric.
Safety (supplemental) (S:X)
Not evaluated.
Automatable (supplemental) (AU:X)
Not evaluated.
Recovery (supplemental) (R:X)
Not evaluated.
Value density (supplemental) (V:X)
Not evaluated.
Vulnerability response effort (supplemental) (RE:X)
Not evaluated.
Provider urgency (supplemental) (U:X)
Not evaluated.
 — — 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92

Weakness enumeration for CVE-2026-53878

GitHub Security Advisory for CVE-2026-53878

GHSA-8qcx-xf44-272x · Severity: medium — An issue was discovered in Django 6.0 before 6.0.7 and 5.2 before 5.2.16. `DomainNameValidator`...

OS Trackers for CVE-2026-53878

vendor priority summary link
debian unimportant CVE-2026-53878 unimportant priority: Debian including 1 source packages (python-django), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2026-53878
suse medium CVE-2026-53878 severity moderate: SUSE including 2 source package names (python-Django, python311-Django), 2 product×package rows across 1 product lines (SUSE Linux Enterprise Module for Package Hub 15 SP7): Known Not Affected 2. https://www.suse.com/security/cve/CVE-2026-53878/
ubuntu medium CVE-2026-53878 medium priority: Ubuntu including 1 source packages (python-django), 9 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): needs-triage 7, ignored 1, released 1. https://ubuntu.com/security/CVE-2026-53878

Affected software / configurations for CVE-2026-53878

Vendor Product Version Raw CPE
djangoproject django >= 5.2, < 5.2.16 cpe:2.3:a:djangoproject:django:*:*:*:*:*:*:*:*
djangoproject django >= 6.0, < 6.0.7 cpe:2.3:a:djangoproject:django:*:*:*:*:*:*:*:*

References for CVE-2026-53878

cvelogic Threat Intelligence