CVE-2026-88829
HighCVSS 7.2Exploitation Probability (EPSS)
Low risk23th percentile - higher than 23% of all known CVEs
Summary
A flaw was found in BusyBox httpd's reverse proxy feature. When the proxy forwards requests matching a URL prefix to a backend server, only the first HTTP request on a TCP connection has its path rewritten. A pipelined second request is relayed verbatim to the backend, bypassing the configured path restrictions.
Risk Assessment
An attacker could access arbitrary paths on the backend server that were not intended to be exposed through the proxy, potentially revealing sensitive resources or administrative functions.
Recommendation
Update BusyBox to a patched version or disable the reverse proxy feature if not required. Consider additional backend-side restrictions independent of the proxy.
Other vulnerabilities in BusyBox
See all- CVE-2026-88836Unknown
This CVE candidate has been rejected by Red Hat Product Security because it is not a security vulnerability. BusyBox internal TLS is intentionally minimal and documents in FEATURE_WGET_HTTPS that it does not verify peer identity or provide full TLS security; missing Finished verify_data checking is consistent with that documented design and does not cross a separate security boundary warranting a CVE.
- CVE-2024-58251Low
In netstat in BusyBox through 1.37.0, local users can launch a network application with an argv[0] containing an ANSI terminal escape sequence, leading to a denial of service (terminal locked up) when netstat is used by a victim.
- CVE-2023-42365Medium
A use-after-free vulnerability was discovered in BusyBox v.1.36.1 via a crafted awk pattern in the awk.c copyvar function.
- CVE-2023-42364Medium
A use-after-free vulnerability exists in BusyBox v1.36.1 in the evaluate function in awk.c. An attacker can cause a denial of service via a crafted awk pattern.
- CVE-2023-42363Medium
A use-after-free vulnerability was discovered in the xasprintf function in xfuncs_printf.c:344 in BusyBox v.1.36.1.
- CVE-2017-16544High
In the add_match function in libbb/lineedit.c in BusyBox through 1.27.2, the tab autocomplete feature does not sanitize filenames, potentially leading to executing any escape sequences in the terminal.
- CVE-2011-5325High
Directory traversal vulnerability in the BusyBox implementation of tar before version 1.22.0 v5 allows remote attackers to point to files outside the current working directory via a symlink.
- CVE-2016-2147High
Integer overflow in the DHCP client (udhcpc) in BusyBox before version 1.25.0 allows remote attackers to cause a denial of service (crash) via a malformed RFC1035-encoded domain name, leading to an out-of-bounds heap write.
- CVE-2016-6301High
The recv_and_process_client_pkt function in networking/ntpd.c in busybox allows remote attackers to cause a denial of service via a forged NTP packet, triggering a communication loop.
- CVE-2026-88841Low
The vulnerability in BusyBox affects the write_status_file() function in the dpkg tool. Failure to reset a stale field cursor between package stanzas leads to out-of-bounds reads and corruption of the status file when removing multiple packages.
Original NVD description (English source)
A flaw was found in BusyBox httpd's reverse proxy feature. When the proxy is configured to forward requests matching a URL prefix to a backend server, only the first HTTP request on a TCP connection has its path rewritten. An attacker can send a pipelined second request that is relayed verbatim to the backend, bypassing the configured path restrictions. This allows accessing arbitrary paths on the backend server that were not intended to be exposed through the proxy.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS