Answer in brief
CVE-2025-39847 records a Medium severity (CVSS 5.5) vulnerability in ppp: fix memory leak in pad_compress_skb. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC CN 4100 (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC CN 4100 (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c <9ca6a040f76c0b149293e430dabab446f3fc8ab7 || >=b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c <87a35a36742df328d0badf4fbc2e56061c15846c || >=b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c <0b21e9cd4559102da798bdcba453b64ecd7be7ee || >=b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c <1d8b354eafb8876d8bdb1bef69c7d2438aacfbe8 || >=b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c <85c1c86a67e09143aa464e9bf09c397816772348 || >=b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c <631fc8ab5beb9e0ec8651fb9875b9a968e7b4ae4 || >=b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c <33a5bac5f14772730d2caf632ae97b6c2ee95044 || >=b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c <4844123fe0b853a4982c02666cb3fd863d701d50 | 9ca6a040f76c0b149293e430dabab446f3fc8ab7, 87a35a36742df328d0badf4fbc2e56061c15846c, 0b21e9cd4559102da798bdcba453b64ecd7be7ee, 1d8b354eafb8876d8bdb1bef69c7d2438aacfbe8, 85c1c86a67e09143aa464e9bf09c397816772348, 631fc8ab5beb9e0ec8651fb9875b9a968e7b4ae4, 33a5bac5f14772730d2caf632ae97b6c2ee95044, 4844123fe0b853a4982c02666cb3fd863d701d50 |
| Linux/Linuxgeneric | 2.6.15 | Not reported |
| Siemens/SIMATIC CN 4100generic | >=0 <V5.0 | V5.0 |
Published upstream
Sep 19, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 28, 2026
In the Linux kernel, the following vulnerability has been resolved: ppp: fix memory leak in pad_compress_skb If alloc_skb() fails in pad_compress_skb(), it returns NULL without releasing the old skb. The caller does: skb = pad_compress_skb(ppp, skb); if (!skb) goto drop; drop: kfree_skb(skb); When pad_compress_skb() returns NULL, the reference to the old skb is lost and kfree_skb(skb) ends up doing nothing, leading to a memory leak. Align pad_compress_skb() semantics with realloc(): only free the old skb if allocation and compression succeed. At the call site, use the new_skb variable so the original skb is not lost when pad_compress_skb() fails.
Quoted source text, attributed separately from HOL analysis.