CVE-2025-39766

{"id": "CVE-2025-39766", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2025-39766", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-06-10T20:40:58.138217Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 1.8}]}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "046f6fd5daefac7f5abdafb436b30f63bc7c602b", "lessThan": "7689ab22de36f8db19095f6bdf11f28cfde92f5c", "versionType": "git"}, {"status": "affected", "version": "046f6fd5daefac7f5abdafb436b30f63bc7c602b", "lessThan": "de04ddd2980b48caa8d7e24a7db2742917a8b280", "versionType": "git"}, {"status": "affected", "version": "046f6fd5daefac7f5abdafb436b30f63bc7c602b", "lessThan": "0dacfc5372e314d1219f03e64dde3ab495a5a25e", "versionType": "git"}, {"status": "affected", "version": "046f6fd5daefac7f5abdafb436b30f63bc7c602b", "lessThan": "710866fc0a64eafcb8bacd91bcb1329eb7e5035f", "versionType": "git"}, {"status": "affected", "version": "046f6fd5daefac7f5abdafb436b30f63bc7c602b", "lessThan": "aa12ee1c1bd260943fd6ab556d8635811c332eeb", "versionType": "git"}, {"status": "affected", "version": "046f6fd5daefac7f5abdafb436b30f63bc7c602b", "lessThan": "ff57186b2cc39766672c4c0332323933e5faaa88", "versionType": "git"}, {"status": "affected", "version": "046f6fd5daefac7f5abdafb436b30f63bc7c602b", "lessThan": "62d591dde4defb1333d202410609c4ddeae060b3", "versionType": "git"}, {"status": "affected", "version": "046f6fd5daefac7f5abdafb436b30f63bc7c602b", "lessThan": "15de71d06a400f7fdc15bf377a2552b0ec437cf5", "versionType": "git"}], "programFiles": ["net/sched/sch_cake.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "4.19"}, {"status": "unaffected", "version": "0", "lessThan": "4.19", "versionType": "semver"}, {"status": "unaffected", "version": "5.4.297", "versionType": "semver", "lessThanOrEqual": "5.4.*"}, {"status": "unaffected", "version": "5.10.241", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.15.190", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.149", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.103", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.44", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.16.4", "versionType": "semver", "lessThanOrEqual": "6.16.*"}, {"status": "unaffected", "version": "6.17", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["net/sched/sch_cake.c"], "defaultStatus": "affected"}]}, {"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "affectedData": [{"vendor": "Siemens", "product": "SIMATIC CN 4100", "versions": [{"status": "affected", "version": "0", "lessThan": "V5.0", "versionType": "custom"}], "defaultStatus": "unknown"}]}], "published": "2025-09-11T17:15:41.623", "references": [{"url": "https://git.kernel.org/stable/c/0dacfc5372e314d1219f03e64dde3ab495a5a25e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/15de71d06a400f7fdc15bf377a2552b0ec437cf5", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/62d591dde4defb1333d202410609c4ddeae060b3", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/710866fc0a64eafcb8bacd91bcb1329eb7e5035f", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/7689ab22de36f8db19095f6bdf11f28cfde92f5c", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/aa12ee1c1bd260943fd6ab556d8635811c332eeb", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/de04ddd2980b48caa8d7e24a7db2742917a8b280", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/ff57186b2cc39766672c4c0332323933e5faaa88", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html", "tags": ["Mailing List", "Third Party Advisory"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html", "tags": ["Mailing List", "Third Party Advisory"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://cert-portal.siemens.com/productcert/html/ssa-032379.html", "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: Make cake_enqueue return NET_XMIT_CN when past buffer_limit\n\nThe following setup can trigger a WARNING in htb_activate due to\nthe condition: !cl->leaf.q->q.qlen\n\ntc qdisc del dev lo root\ntc qdisc add dev lo root handle 1: htb default 1\ntc class add dev lo parent 1: classid 1:1 \\\n htb rate 64bit\ntc qdisc add dev lo parent 1:1 handle f: \\\n cake memlimit 1b\nping -I lo -f -c1 -s64 -W0.001 127.0.0.1\n\nThis is because the low memlimit leads to a low buffer_limit, which\ncauses packet dropping. However, cake_enqueue still returns\nNET_XMIT_SUCCESS, causing htb_enqueue to call htb_activate with an\nempty child qdisc. We should return NET_XMIT_CN when packets are\ndropped from the same tin and flow.\n\nI do not believe return value of NET_XMIT_CN is necessary for packet\ndrops in the case of ack filtering, as that is meant to optimize\nperformance, not to signal congestion."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet/sched: Hacer que cake_enqueue devuelva NET_XMIT_CN cuando se excede el buffer_limit\n\nLa siguiente configuraci\u00f3n puede activar una ADVERTENCIA en htb_activate debido a la condici\u00f3n: !cl->leaf.q->q.qlen\n\ntc qdisc del dev lo root\ntc qdisc add dev lo root handle 1: htb default 1\ntc class add dev lo parent 1: classid 1:1 \\\n htb rate 64bit\ntc qdisc add dev lo parent 1:1 handle f: \\\n cake memlimit 1b\nping -I lo -f -c1 -s64 -W0.001 127.0.0.1\n\nEsto se debe a que el memlimit bajo conduce a un buffer_limit bajo, lo que provoca la ca\u00edda de paquetes. Sin embargo, cake_enqueue todav\u00eda devuelve NET_XMIT_SUCCESS, haciendo que htb_enqueue llame a htb_activate con un qdisc hijo vac\u00edo. Deber\u00edamos devolver NET_XMIT_CN cuando los paquetes se descartan del mismo tin y flujo.\n\nNo creo que el valor de retorno de NET_XMIT_CN sea necesario para la ca\u00edda de paquetes en el caso del filtrado de ACKs, ya que eso est\u00e1 destinado a optimizar el rendimiento, no a se\u00f1alar congesti\u00f3n."}], "lastModified": "2026-10-19T21:10:00.160", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DB980BDC-B34E-41B6-BF6D-8AF3F2450143", "versionEndExcluding": "5.4.297", "versionStartIncluding": "4.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D0D21C35-EB8A-488A-BBF9-403E4817E5DD", "versionEndExcluding": "5.10.241", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "AD9E597F-3DDE-4D7E-976C-463D0611F13F", "versionEndExcluding": "5.15.190", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "FDBE8280-8983-4D2D-943D-2E6D0104E2D8", "versionEndExcluding": "6.1.149", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F2293654-7169-49B5-8D0D-EE51EF8B8E48", "versionEndExcluding": "6.6.103", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "12351F24-1133-4775-960C-F2B47E81298B", "versionEndExcluding": "6.12.44", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "AFC28995-B8C3-4B68-8CB6-78E792B6629D", "versionEndExcluding": "6.16.4", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "327D22EF-390B-454C-BD31-2ED23C998A1C"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C730CD9A-D969-4A8E-9522-162AAF7C0EE9"}], "operator": "OR"}]}, {"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "FA6FEEC2-9F11-4643-8827-749718254FED"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}