<?xml version='1.0' encoding='UTF-8'?>
<?xml-stylesheet href="/static/style.xsl" type="text/xsl"?>
<rss xmlns:atom="http://www.w3.org/2005/Atom" xmlns:content="http://purl.org/rss/1.0/modules/content/" version="2.0">
  <channel>
    <title>Most recent sightings.</title>
    <link>https://vulnerability.circl.lu</link>
    <description>Contains only the most 10 recent sightings.</description>
    <docs>http://www.rssboard.org/rss-specification</docs>
    <generator>python-feedgen</generator>
    <language>en</language>
    <lastBuildDate>Wed, 27 May 2026 18:44:09 +0000</lastBuildDate>
    <item>
      <title>c8884148-c039-47a9-8306-211b55a34ea7</title>
      <link>https://vulnerability.circl.lu/sighting/c8884148-c039-47a9-8306-211b55a34ea7/export</link>
      <description>{"uuid": "c8884148-c039-47a9-8306-211b55a34ea7", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2021-47506", "type": "published-proof-of-concept", "source": "https://t.me/DarkWebInformer_CVEAlerts/16494", "content": "\ud83d\udd17 DarkWebInformer.com - Cyber Threat Intelligence\n\ud83d\udccc CVE ID: CVE-2021-47506\n\ud83d\udd25 CVSS Score: N/A\n\ud83d\udd39 Description: In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix use-after-free due to delegation race\n\nA delegation break could arrive as soon as we've called vfs_setlease.  A\ndelegation break runs a callback which immediately (in\nnfsd4_cb_recall_prepare) adds the delegation to del_recall_lru.  If we\nthen exit nfs4_set_delegation without hashing the delegation, it will be\nfreed as soon as the callback is done with it, without ever being\nremoved from del_recall_lru.\n\nSymptoms show up later as use-after-free or list corruption warnings,\nusually in the laundromat thread.\n\nI suspect aba2072f4523 \"nfsd: grant read delegations to clients holding\nwrites\" made this bug easier to hit, but I looked as far back as v3.0\nand it looks to me it already had the same problem.  So I'm not sure\nwhere the bug was introduced; it may have been there from the beginning.\n\ud83d\udccf Published: 2024-05-24T15:01:52.746Z\n\ud83d\udccf Modified: 2025-05-15T12:32:37.708Z\n\ud83d\udd17 References:\n1. https://git.kernel.org/stable/c/04a8d07f3d58308b92630045560799a3faa3ebce\n2. https://git.kernel.org/stable/c/348714018139c39533c55661a0c7c990671396b4\n3. https://git.kernel.org/stable/c/33645d3e22720cac1e4548f8fef57bf0649536ee\n4. https://git.kernel.org/stable/c/2becaa990b93cbd2928292c0b669d3abb6cf06d4\n5. https://git.kernel.org/stable/c/e0759696de6851d7536efddfdd2dfed4c4df1f09\n6. https://git.kernel.org/stable/c/eeb0711801f5e19ef654371b627682aed3b11373\n7. https://git.kernel.org/stable/c/148c816f10fd11df27ca6a9b3238cdd42fa72cd3\n8. https://git.kernel.org/stable/c/548ec0805c399c65ed66c6641be467f717833ab5", "creation_timestamp": "2025-05-15T13:33:41.000000Z"}</description>
      <content:encoded>{"uuid": "c8884148-c039-47a9-8306-211b55a34ea7", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2021-47506", "type": "published-proof-of-concept", "source": "https://t.me/DarkWebInformer_CVEAlerts/16494", "content": "\ud83d\udd17 DarkWebInformer.com - Cyber Threat Intelligence\n\ud83d\udccc CVE ID: CVE-2021-47506\n\ud83d\udd25 CVSS Score: N/A\n\ud83d\udd39 Description: In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix use-after-free due to delegation race\n\nA delegation break could arrive as soon as we've called vfs_setlease.  A\ndelegation break runs a callback which immediately (in\nnfsd4_cb_recall_prepare) adds the delegation to del_recall_lru.  If we\nthen exit nfs4_set_delegation without hashing the delegation, it will be\nfreed as soon as the callback is done with it, without ever being\nremoved from del_recall_lru.\n\nSymptoms show up later as use-after-free or list corruption warnings,\nusually in the laundromat thread.\n\nI suspect aba2072f4523 \"nfsd: grant read delegations to clients holding\nwrites\" made this bug easier to hit, but I looked as far back as v3.0\nand it looks to me it already had the same problem.  So I'm not sure\nwhere the bug was introduced; it may have been there from the beginning.\n\ud83d\udccf Published: 2024-05-24T15:01:52.746Z\n\ud83d\udccf Modified: 2025-05-15T12:32:37.708Z\n\ud83d\udd17 References:\n1. https://git.kernel.org/stable/c/04a8d07f3d58308b92630045560799a3faa3ebce\n2. https://git.kernel.org/stable/c/348714018139c39533c55661a0c7c990671396b4\n3. https://git.kernel.org/stable/c/33645d3e22720cac1e4548f8fef57bf0649536ee\n4. https://git.kernel.org/stable/c/2becaa990b93cbd2928292c0b669d3abb6cf06d4\n5. https://git.kernel.org/stable/c/e0759696de6851d7536efddfdd2dfed4c4df1f09\n6. https://git.kernel.org/stable/c/eeb0711801f5e19ef654371b627682aed3b11373\n7. https://git.kernel.org/stable/c/148c816f10fd11df27ca6a9b3238cdd42fa72cd3\n8. https://git.kernel.org/stable/c/548ec0805c399c65ed66c6641be467f717833ab5", "creation_timestamp": "2025-05-15T13:33:41.000000Z"}</content:encoded>
      <guid isPermaLink="false">https://vulnerability.circl.lu/sighting/c8884148-c039-47a9-8306-211b55a34ea7/export</guid>
      <pubDate>Thu, 15 May 2025 13:33:41 +0000</pubDate>
    </item>
  </channel>
</rss>
