CVE-2025-12642

unknown

Published — · Modified —

💬 Discuss on Community ✚ Propose mitigation

CVSS v3

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CVSS v4 NEW

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not yet in upstream

VIR risk

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Description

lighttpd1.4.80 incorrectly merged trailer fields into headers after http request parsing. This behavior can be exploited to conduct HTTP Header Smuggling attacks. Successful exploitation may allow an attacker to: * Bypass access control rules * Inject unsafe input into backend logic that trusts request headers * Execute HTTP Request Smuggling attacks under some conditions This issue affects lighttpd1.4.80

Predictions

Exploit likelihood

20%

Patch ETA

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Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

OS impact

Debian Fixed 5 releases

Version	Status	Fixed in
trixie	Fixed	`0`
sid	Fixed	`0`
forky	Fixed	`0`
bullseye	Fixed	`0`
bookworm	Fixed	`0`

References

https://security-tracker.debian.org/tracker/CVE-2025-12642

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.