CVE-2025-32907 addressed memory amplification when a client repeated the same range many times in a single Range header. Commit 9bb92f7a corrected merge correctness in soup_message_headers_get_ranges_internal() in libsoup/soup-message-headers.c, but the coalescing loop still removes merged ranges using g_array_remove_index() for each coalesced element. Because GArray is contiguous, each mid-array removal performs an O(N) memmove. When many identical satisfiable ranges are supplied (for example bytes=0-0 repeated thousands of times), the loop performs O(N²) work coalescing them into a single range.
The vulnerable path is reachable server-side from handle_partial_get() in libsoup/server/http1/soup-server-message-io-http1.c when a SoupServer handler returns HTTP 200 with a non-empty body. No authentication is required. The number of ranges is bounded only by the maximum request header size (~100 KiB), allowing roughly 25,000 ranges per request. Reporter measurements on libsoup HEAD containing the CVE-2025-32907 fix show ~90 ms single-core CPU per such request at the wire maximum, blocking the server's event loop for that duration.
This is a CPU exhaustion / availability issue only. No memory corruption or information disclosure occurs.
Affected: libsoup versions containing the CVE-2025-32907 fix but not merge request !550.
Fixed upstream: MR !550 merged 2026-08-20, replacing per-element removal with O(N) in-place compaction and rejecting Range headers requesting more than 200 ranges.
Upstream report: https://gitlab.gnome.org/GNOME/libsoup/-/issues/538
Related: CVE-2025-32907
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | affected | — |
No data.
No data.
No data available yet.
Vendor Workaround
Upgrade to a libsoup version containing merge request !550 (O(N) range coalescing and 200-range limit). Until patched, restrict network access to services using SoupServer, or terminate connections that send Range headers with excessive range counts.
Tracking
Sign in to view the affected projects.
No advisories yet.
Tue, 25 Aug 2026 21:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | An algorithmic complexity flaw exists in libsoup's HTTP Range header processing that persists after the CVE-2025-32907 fix. CVE-2025-32907 addressed memory amplification when a client repeated the same range many times in a single Range header. Commit 9bb92f7a corrected merge correctness in soup_message_headers_get_ranges_internal() in libsoup/soup-message-headers.c, but the coalescing loop still removes merged ranges using g_array_remove_index() for each coalesced element. Because GArray is contiguous, each mid-array removal performs an O(N) memmove. When many identical satisfiable ranges are supplied (for example bytes=0-0 repeated thousands of times), the loop performs O(N²) work coalescing them into a single range. The vulnerable path is reachable server-side from handle_partial_get() in libsoup/server/http1/soup-server-message-io-http1.c when a SoupServer handler returns HTTP 200 with a non-empty body. No authentication is required. The number of ranges is bounded only by the maximum request header size (~100 KiB), allowing roughly 25,000 ranges per request. Reporter measurements on libsoup HEAD containing the CVE-2025-32907 fix show ~90 ms single-core CPU per such request at the wire maximum, blocking the server's event loop for that duration. This is a CPU exhaustion / availability issue only. No memory corruption or information disclosure occurs. Affected: libsoup versions containing the CVE-2025-32907 fix but not merge request !550. Fixed upstream: MR !550 merged 2026-08-20, replacing per-element removal with O(N) in-place compaction and rejecting Range headers requesting more than 200 ranges. Upstream report: https://gitlab.gnome.org/GNOME/libsoup/-/issues/538 Related: CVE-2025-32907 | |
| Title | Libsoup3: libsoup: quadratic cpu denial of service in http range coalescing after cve-2025-32907 fix | |
| First Time appeared |
Redhat
Redhat enterprise Linux |
|
| Weaknesses | CWE-407 | |
| CPEs | cpe:/o:redhat:enterprise_linux:10 | |
| Vendors & Products |
Redhat
Redhat enterprise Linux |
|
| References |
| |
| Metrics |
cvssV3_1
|
MITRE
Status: PUBLISHED
Assigner: redhat
Published:
Updated: 2026-08-25T20:36:45.808Z
Reserved: 2026-08-21T05:11:09.007Z
Link: CVE-2026-77680
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-08-25T21:17:46.243
Modified: 2026-08-25T21:17:46.243
Link: CVE-2026-77680
Redhat
No data.
OpenCVE Enrichment
No data.