Potential exposure of private data via whitespace padding in Vary header

Summary

CVECVE-2026-48587
StatePUBLISHED
AssignerDSF
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-03 14:16:44 UTC
Updated2026-06-03 14:16:44 UTC
DescriptionAn issue was discovered in Django 5.2 before 5.2.15 and 6.0 before 6.0.6. `django.utils.cache.has_vary_header()` in Django does not strip leading or trailing whitespace from `Vary` response header values before comparison, which allows remote attackers to read cached responses via requests to URLs whose responses contain whitespace-padded Vary header values. 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 Navid Rezazadeh for reporting this issue.

Risk And Classification

Primary CVSS: v4.0 2.3 LOW from 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/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

Problem Types: CWE-1023 | CWE-1023 CWE-1023: Incomplete Comparison with Missing Factors


VersionSourceTypeScoreSeverityVector
4.06a34fbeb-21d4-45e7-8e0a-62b95bc12c92Secondary2.3LOWCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/C...
4.0CNADECLARED2.3LOWCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
3.16a34fbeb-21d4-45e7-8e0a-62b95bc12c92Secondary3.1LOWCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
3.1CNADECLARED3.1LOWCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
Passive
Confidentiality
Low
Integrity
None
Availability
None
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/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

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Djangoproject Django affected 6.0 6.0.6 python Not specified
CNA Djangoproject Django unaffected 6.0.6 python Not specified
CNA Djangoproject Django affected 5.2 5.2.15 python Not specified
CNA Djangoproject Django unaffected 5.2.15 python Not specified

References

ReferenceSourceLinkTags
www.djangoproject.com/weblog/2026/jun/03/security-releases 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92 www.djangoproject.com
groups.google.com/g/django-announce 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92 groups.google.com
docs.djangoproject.com/en/dev/releases/security 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92 docs.djangoproject.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Navid Rezazadeh (en)

CNA: Jake Howard (en)

CNA: Natalia Bidart (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-05-11T00:00:00.000ZInitial report received.
CNA2026-05-26T00:00:00.000ZVulnerability confirmed.
CNA2026-06-03T08:00:00.000ZSecurity release issued.
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