Answer in brief
CVE-2021-47259 records a High severity (CVSS 7.8) vulnerability in NFS: Fix use-after-free in nfs4_init_client(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), linux/linux_kernel (generic), linux/linux_kernel (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 7.8. 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), linux/linux_kernel (generic), linux/linux_kernel (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc5:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=8dcbec6d20eb881ba368d0aebc3a8a678aebb1da <c7eab9e2d7b4e983ce280276fb920af649955897 || >=8dcbec6d20eb881ba368d0aebc3a8a678aebb1da <42c10b0db064e45f5c5ae7019bbf2168ffab766c || >=8dcbec6d20eb881ba368d0aebc3a8a678aebb1da <3e3c7ebbfac152d08be75c92802a64a1f6471a15 || >=8dcbec6d20eb881ba368d0aebc3a8a678aebb1da <c3b6cf64dfe4ef96e7341508d50d6998da7062c7 || >=8dcbec6d20eb881ba368d0aebc3a8a678aebb1da <72651c6579a25317a90536181d311c663d0329ab || >=8dcbec6d20eb881ba368d0aebc3a8a678aebb1da <476bdb04c501fc64bf3b8464ffddefc8dbe01577 | c7eab9e2d7b4e983ce280276fb920af649955897, 42c10b0db064e45f5c5ae7019bbf2168ffab766c, 3e3c7ebbfac152d08be75c92802a64a1f6471a15, c3b6cf64dfe4ef96e7341508d50d6998da7062c7, 72651c6579a25317a90536181d311c663d0329ab, 476bdb04c501fc64bf3b8464ffddefc8dbe01577 |
| Linux/Linuxgeneric | 4.13 | Not reported |
| linux/linux_kernelgeneric | 4.13 | Not reported |
| linux/linux_kernelgeneric | >=8dcbec6d20eb <476bdb04c501 | 476bdb04c501 |
Published upstream
May 21, 2024
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 4, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 4, 2026
In the Linux kernel, the following vulnerability has been resolved: NFS: Fix use-after-free in nfs4_init_client() KASAN reports a use-after-free when attempting to mount two different exports through two different NICs that belong to the same server. Olga was able to hit this with kernels starting somewhere between 5.7 and 5.10, but I traced the patch that introduced the clear_bit() call to 4.13. So something must have changed in the refcounting of the clp pointer to make this call to nfs_put_client() the very last one.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2021-47259 records a High severity (CVSS 7.8) vulnerability in NFS: Fix use-after-free in nfs4_init_client(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), linux/linux_kernel (generic), linux/linux_kernel (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 7.8. 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), linux/linux_kernel (generic), linux/linux_kernel (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc5:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=8dcbec6d20eb881ba368d0aebc3a8a678aebb1da <c7eab9e2d7b4e983ce280276fb920af649955897 || >=8dcbec6d20eb881ba368d0aebc3a8a678aebb1da <42c10b0db064e45f5c5ae7019bbf2168ffab766c || >=8dcbec6d20eb881ba368d0aebc3a8a678aebb1da <3e3c7ebbfac152d08be75c92802a64a1f6471a15 || >=8dcbec6d20eb881ba368d0aebc3a8a678aebb1da <c3b6cf64dfe4ef96e7341508d50d6998da7062c7 || >=8dcbec6d20eb881ba368d0aebc3a8a678aebb1da <72651c6579a25317a90536181d311c663d0329ab || >=8dcbec6d20eb881ba368d0aebc3a8a678aebb1da <476bdb04c501fc64bf3b8464ffddefc8dbe01577 | c7eab9e2d7b4e983ce280276fb920af649955897, 42c10b0db064e45f5c5ae7019bbf2168ffab766c, 3e3c7ebbfac152d08be75c92802a64a1f6471a15, c3b6cf64dfe4ef96e7341508d50d6998da7062c7, 72651c6579a25317a90536181d311c663d0329ab, 476bdb04c501fc64bf3b8464ffddefc8dbe01577 |
| Linux/Linuxgeneric | 4.13 | Not reported |
| linux/linux_kernelgeneric | 4.13 | Not reported |
| linux/linux_kernelgeneric | >=8dcbec6d20eb <476bdb04c501 | 476bdb04c501 |
Published upstream
May 21, 2024
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 4, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 4, 2026
In the Linux kernel, the following vulnerability has been resolved: NFS: Fix use-after-free in nfs4_init_client() KASAN reports a use-after-free when attempting to mount two different exports through two different NICs that belong to the same server. Olga was able to hit this with kernels starting somewhere between 5.7 and 5.10, but I traced the patch that introduced the clear_bit() call to 4.13. So something must have changed in the refcounting of the clp pointer to make this call to nfs_put_client() the very last one.
Quoted source text, attributed separately from HOL analysis.