Is CVE-2026-108082 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-108082 being exploited in the wild.

How severe is CVE-2026-108082?

High severity, with a CVSS score of 4, published 15 October 2026.

Which products and versions are affected?

symfony/http-foundation (Packagist) >= 6.0.1, = 6.0.1, < 6.4.46, ECOSYSTEM:introduced=6.0.1,fixed=6.4.46; Symfony Http Foundation 4.1.0-BETA1 through 5.4.53; 6.0.0-BETA1 through 6.4.45; 7.0.0-BETA1 through 7.4.18; 8.0.0-BETA1 through 8.1.6.

Is there a fix for CVE-2026-108082?

Yes. symfony/http-foundation (Packagist): upgrade to 6.4.46 or later; symfony/symfony (Packagist): upgrade to 6.4.46 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-108082 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-108082?

Check whether you run symfony/http-foundation (Packagist), symfony/symfony (Packagist) or Symfony Http Foundation at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-108082: Symfony HTTP Foundation ReDoS in HeaderUtils::split()

Q: Is there a fix for CVE-2026-108082?

Yes. symfony/http-foundation (Packagist): upgrade to 6.4.46 or later; symfony/symfony (Packagist): upgrade to 6.4.46 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-108082 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-108082?

Check whether you run symfony/http-foundation (Packagist), symfony/symfony (Packagist) or Symfony Http Foundation at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-108082 · Severity: high · CVSS 4 · Published 2026-10-15

Symfony's HTTP Foundation library parses HTTP headers using a regular expression vulnerable to catastrophic backtracking when processing whitespace-heavy input. An attacker can send a specially crafted Cache-Control header that causes the application to consume excessive CPU, leading to denial of service. Any web application using Symfony to handle HTTP requests is affected without requiring authentication.

Technologies: symfony/http-foundation (Packagist), symfony/symfony (Packagist), Symfony Http Foundation. Vendors: Packagist, Symfony.

Quick answers

Is CVE-2026-108082 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-108082 being exploited in the wild.
How severe is CVE-2026-108082?: High severity, with a CVSS score of 4, published 15 October 2026.
Which products and versions are affected?: symfony/http-foundation (Packagist) >= 6.0.1, < 6.4.46, ECOSYSTEM:introduced=6.0.1,fixed=6.4.46; symfony/symfony (Packagist) >= 6.0.1, < 6.4.46, ECOSYSTEM:introduced=6.0.1,fixed=6.4.46; Symfony Http Foundation 4.1.0-BETA1 through 5.4.53; 6.0.0-BETA1 through 6.4.45; 7.0.0-BETA1 through 7.4.18; 8.0.0-BETA1 through 8.1.6.
Is there a fix for CVE-2026-108082?: Yes. symfony/http-foundation (Packagist): upgrade to 6.4.46 or later; symfony/symfony (Packagist): upgrade to 6.4.46 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-108082 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-108082?: Check whether you run symfony/http-foundation (Packagist), symfony/symfony (Packagist) or Symfony Http Foundation at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

symfony/http-foundation (Packagist): upgrade to 6.4.46 or later
```
composer require symfony/http-foundation:^6.4.46
```
symfony/symfony (Packagist): upgrade to 6.4.46 or later
```
composer require symfony/symfony:^6.4.46
```

Technical details

The HeaderUtils::split() function uses a regex pattern with alternation and lookahead/lookbehind assertions that allows exponential interpretation of whitespace characters before a separator. A run of N spaces can be divided among quantifier iterations in 2^N ways, forcing the regex engine to backtest all paths. This causes exponential CPU consumption (roughly doubling per additional space); beyond the pcre.backtrack_limit threshold (18+ spaces), parsing silently fails and returns an empty array, causing header directives to be dropped.

Affected products

Symfony HTTP Foundation 4.1.0-BETA1 through 5.4.53; 6.0.0-BETA1 through 6.4.45; 7.0.0-BETA1 through 7.4.18; 8.0.0-BETA1 through 8.1.6

Identifiers

CVE-2026-108082
GHSA-r925-mgvr-h9cc

Timeline

2026-10-15: disclosed: CVE-2026-108082 published
2026-09-14: patched: Fix merged in GitHub PR #66048

References

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