CVE-2026-108082 sensiolabs CVE debrief

Who should care

Defenders and developers using the symfony/http-foundation package, especially in applications handling HTTP requests, should assess their exposure and take necessary actions. This includes verifying affected versions, upgrading or patching as needed, and monitoring for suspicious Cache-Control headers. The vulnerability can lead to denial-of-service attacks and impact application performance and availability.

Why it matters

Defenders should care about this ReDoS vulnerability in Symfony's HeaderUtils::split() method as it can be exploited through the Cache-Control request header, potentially leading to denial-of-service attacks and impacting application performance and availability.

• Potential denial-of-service attacks through CPU-intensive header parsing
• Possible impact on application performance and availability

Technical summary

The HeaderUtils::split() method in Symfony is vulnerable to a ReDoS attack when parsing header values with a specific pattern. This can be exploited through the Cache-Control request header, potentially leading to denial-of-service attacks. The vulnerability affects various versions of the symfony/http-foundation package. Defenders should prioritize patching or mitigating this vulnerability, especially in applications handling HTTP requests. The CVE record and source item provide details on the vulnerability, including its impact on the symfony/http-foundation package and potential denial-of-service attacks.

Defensive priority

Defenders should prioritize patching or mitigating this vulnerability, especially in applications handling HTTP requests.

Recommended defensive actions

• Assess exposure and apply patches or mitigations
• Monitor for suspicious Cache-Control headers
• Verify affected versions and upgrade or patch as needed
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the vulnerability, including its impact on the symfony/http-foundation package and potential denial-of-service attacks. The vulnerability can be exploited through the Cache-Control request header, potentially leading to denial-of-service attacks and impacting application performance and availability. There are no known exploits in the wild, but defenders should verify affected versions and upgrade or patch as needed. The symfony/http-foundation package is widely used in web and console

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.