Description
A resource leak in gw_backend.c in lighttpd 1.4.56 through 1.4.66 could lead to a denial of service (connection-slot exhaustion) after a large amount of anomalous TCP behavior by clients. It is related to RDHUP mishandling in certain HTTP/1.1 chunked situations. Use of mod_fastcgi is, for example, affected. This is fixed in 1.4.67.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | lighttpd | 1.4.67-1 | — |
| Debian 13 | lighttpd | 1.4.67-1 | — |
| Debian 12 | lighttpd | 1.4.67-1 | — |
| Debian 11 | lighttpd | 1.4.59-1+deb11u2 | DSA-5243-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | lighttpd | 1.4.63-1ubuntu3.1 | USN-5903-1 |
| Ubuntu 20.04 LTS | lighttpd | 1.4.55-1ubuntu1.20.04.2 | USN-5903-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 14.04 LTS | lighttpd | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP4 | lighttpd | 1.4.67-bp154.2.6.1 | openSUSE-SU-2022:10140-1 |
| SUSE Package Hub 15 SP3 | lighttpd | 1.4.67-bp154.2.6.1 | openSUSE-SU-2022:10140-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | lighttpd | 1.4.67-2.1 | openSUSE-SU-2024:12382-1 |
| openSUSE Leap 15.4 | lighttpd | 1.4.67-bp154.2.6.1 | openSUSE-SU-2022:10140-1 |
| openSUSE Leap 15.3 | lighttpd | 1.4.67-bp154.2.6.1 | openSUSE-SU-2022:10140-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | lighttpd | 1.4.67-r0 | — |
| Alpine v3.23 | lighttpd | 1.4.67-r0 | — |
| Alpine v3.22 | lighttpd | 1.4.67-r0 | — |
| Alpine v3.21 | lighttpd | 1.4.67-r0 | — |
| Alpine v3.20 | lighttpd | 1.4.67-r0 | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | lighttpd | 1.4.67-r0 | — |
| Alpine v3.18 | lighttpd | 1.4.67-r0 | — |
| Alpine v3.17 | lighttpd | 1.4.67-r0 | — |
| Alpine v3.16 | lighttpd | 1.4.67-r0 | — |
| Alpine v3.15 | lighttpd | 1.4.67-r0 | — |
Advisories 8
- USN-5903-1 lighttpd vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DSA-5243-1 lighttpd - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:12382-1 lighttpd-1.4.67-2.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2022:10140-1 Security update for lighttpd SUSE / openSUSE Security Updates · Feb 4, 2026
- SSA-806742 SSA-806742: Multiple Vulnerabilities in SCALANCE XCM-/XRM-300 before V2.4 Siemens ProductCERT · Feb 13, 2024
- ICSA-24-046-11 Siemens SCALANCE XCM-/XRM-300 CISA ICS & IT advisories · Feb 13, 2024
- WID-SEC-2023-0561 Xerox FreeFlow Print Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · May 18, 2023
- WID-SEC-2022-1585 lighttpd: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Feb 28, 2023