CVE-2026-108082 Symfony HTTP Foundation - Denial of Service

Symfony HTTP Foundation < 5.4.54, < 6.4.46, < 7.4.19, and < 8.1.7 contains a denial of service caused by exponential backtracking in HeaderUtils::split() when parsing Cache-Control headers, letting remote attackers cause high CPU usage, exploit requires sending crafted HTTP requests.

CVSS base score 8.7 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
View the NVD record ↗

Details

Type
Denial of Service
Impact
Denial Of Service
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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
Published
15 October 2026
Updated
15 October 2026
Weakness
CWE-1333

Vendor fix

Upgrade to versions 5.4.54, 6.4.46, 7.4.19, 8.1.7 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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