Evidence used
- No CISA KEV confirmation is currently recorded.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 0.64% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2024
CVE-2023-52610High confidence
net/sched: act_ct: fix skb leak and crash on ooo frags
Linux · Linux
7.5HighCVSS 3.1
Within 7 days
Patch availableHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Linux Linux and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Distribution package intelligence
4 package statesRelease-specific package status
Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.6.15-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.1.76-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian forkyforky · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.6.15-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.6.15-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Patch available01
What, why and how
In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ct: fix skb leak and crash on ooo frags act_ct adds skb->users before defragmentation. If frags arrive in order, the last frag's reference is reset in: inet_frag_reasm_prepare skb_morph which is not straightforward. However when frags arrive out of order, nobody unref the last frag, and all frags are leaked. The situation is even worse, as initiating packet capture can lead to a crash[0] when skb has been cloned and shared at the same time. Fix the issue by removing skb_get() before defragmentation. act_ct returns TC_ACT_CONSUMED when defrag failed or in progress. [0]: [ 843.804823] ------------[ cut here ]------------ [ 843.809659] kernel BUG at net/core/skbuff.c:2091! [ 843.814516] invalid opcode: 0000 [#1] PREEMPT SMP [ 843.819296] CPU: 7 PID: 0 Comm: swapper/7 Kdump: loaded Tainted: G S 6.7.0-rc3 #2 [ 843.824107] Hardware name: XFUSION 1288H V6/BC13MBSBD, BIOS 1.29 11/25/2022 [ 843.828953] RIP: 0010:pskb_expand_head+0x2ac/0x300 [ 843.833805] Code: 8b 70 28 48 85 f6 74 82 48 83 c6 08 bf 01 00 00 00 e8 38 bd ff ff 8b 83 c0 00 00 00 48 03 83 c8 00 00 00 e9 62 ff ff ff 0f 0b <0f> 0b e8 8d d0 ff ff e9 b3 fd ff ff 81 7c 24 14 40 01 00 00 4c 89 [ 843.843698] RSP: 0018:ffffc9000cce07c0 EFLAGS: 00010202 [ 843.848524] RAX: 0000000000000002 RBX: ffff88811a211d00 RCX: 0000000000000820 [ 843.853299] RDX: 0000000000000640 RSI: 0000000000000000 RDI: ffff88811a211d00 [ 843.857974] RBP: ffff888127d39518 R08: 00000000bee97314 R09: 0000000000000000 [ 843.862584] R10: 0000000000000000 R11: ffff8881109f0000 R12: 0000000000000880 [ 843.867147] R13: ffff888127d39580 R14: 0000000000000640 R15: ffff888170f7b900 [ 843.871680] FS: 0000000000000000(0000) GS:ffff889ffffc0000(0000) knlGS:0000000000000000 [ 843.876242] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 843.880778] CR2: 00007fa42affcfb8 CR3: 000000011433a002 CR4: 0000000000770ef0 [ 843.885336] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 843.889809] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 843.894229] PKRU: 55555554 [ 843.898539] Call Trace: [ 843.902772] <IRQ> [ 843.906922] ? __die_body+0x1e/0x60 [ 843.911032] ? die+0x3c/0x60 [ 843.915037] ? do_trap+0xe2/0x110 [ 843.918911] ? pskb_expand_head+0x2ac/0x300 [ 843.922687] ? do_error_trap+0x65/0x80 [ 843.926342] ? pskb_expand_head+0x2ac/0x300 [ 843.929905] ? exc_invalid_op+0x50/0x60 [ 843.933398] ? pskb_expand_head+0x2ac/0x300 [ 843.936835] ? asm_exc_invalid_op+0x1a/0x20 [ 843.940226] ? pskb_expand_head+0x2ac/0x300 [ 843.943580] inet_frag_reasm_prepare+0xd1/0x240 [ 843.946904] ip_defrag+0x5d4/0x870 [ 843.950132] nf_ct_handle_fragments+0xec/0x130 [nf_conntrack] [ 843.953334] tcf_ct_act+0x252/0xd90 [act_ct] [ 843.956473] ? tcf_mirred_act+0x516/0x5a0 [act_mirred] [ 843.959657] tcf_action_exec+0xa1/0x160 [ 843.962823] fl_classify+0x1db/0x1f0 [cls_flower] [ 843.966010] ? skb_clone+0x53/0xc0 [ 843.969173] tcf_classify+0x24d/0x420 [ 843.972333] tc_run+0x8f/0xf0 [ 843.975465] __netif_receive_skb_core+0x67a/0x1080 [ 843.978634] ? dev_gro_receive+0x249/0x730 [ 843.981759] __netif_receive_skb_list_core+0x12d/0x260 [ 843.984869] netif_receive_skb_list_internal+0x1cb/0x2f0 [ 843.987957] ? mlx5e_handle_rx_cqe_mpwrq_rep+0xfa/0x1a0 [mlx5_core] [ 843.991170] napi_complete_done+0x72/0x1a0 [ 843.994305] mlx5e_napi_poll+0x28c/0x6d0 [mlx5_core] [ 843.997501] __napi_poll+0x25/0x1b0 [ 844.000627] net_rx_action+0x256/0x330 [ 844.003705] __do_softirq+0xb3/0x29b [ 844.006718] irq_exit_rcu+0x9e/0xc0 [ 844.009672] common_interrupt+0x86/0xa0 [ 844.012537] </IRQ> [ 844.015285] <TASK> [ 844.017937] asm_common_interrupt+0x26/0x40 [ 844.020591] RIP: 0010:acpi_safe_halt+0x1b/0x20 [ 844.023247] Code: ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 65 48 8b 04 25 00 18 03 00 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 81 d0 44 00 fb ---truncated---
What
In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ct: fix skb leak and crash on ooo frags act_ct adds skb->users before defragmentation. If frags arrive in order, the last frag's reference is reset in: inet_frag_reasm_prepare skb_morph which is not straightforward. However when frags arrive out of order, nobody unref the last frag, and all frags are leaked. The situation is even worse, as initiating packet capture can lead to a crash[0] when skb has been cloned and shared at the same time. Fix the issue by removing skb_get() before defragmentation. act_ct returns TC_ACT_CONSUMED when defrag failed or in progress. [0]: [ 843.804823] ------------[ cut here ]------------ [ 843.809659] kernel BUG at net/core/skbuff.c:2091! [ 843.814516] invalid opcode: 0000 [#1] PREEMPT SMP [ 843.819296] CPU: 7 PID: 0 Comm: swapper/7 Kdump: loaded Tainted: G S 6.7.0-rc3 #2 [ 843.824107] Hardware name: XFUSION 1288H V6/BC13MBSBD, BIOS 1.29 11/25/2022 [ 843.828953] RIP: 0010:pskb_expand_head+0x2ac/0x300 [ 843.833805] Code: 8b 70 28 48 85 f6 74 82 48 83 c6 08 bf 01 00 00 00 e8 38 bd ff ff 8b 83 c0 00 00 00 48 03 83 c8 00 00 00 e9 62 ff ff ff 0f 0b <0f> 0b e8 8d d0 ff ff e9 b3 fd ff ff 81 7c 24 14 40 01 00 00 4c 89 [ 843.843698] RSP: 0018:ffffc9000cce07c0 EFLAGS: 00010202 [ 843.848524] RAX: 0000000000000002 RBX: ffff88811a211d00 RCX: 0000000000000820 [ 843.853299] RDX: 0000000000000640 RSI: 0000000000000000 RDI: ffff88811a211d00 [ 843.857974] RBP: ffff888127d39518 R08: 00000000bee97314 R09: 0000000000000000 [ 843.862584] R10: 0000000000000000 R11: ffff8881109f0000 R12: 0000000000000880 [ 843.867147] R13: ffff888127d39580 R14: 0000000000000640 R15: ffff888170f7b900 [ 843.871680] FS: 0000000000000000(0000) GS:ffff889ffffc0000(0000) knlGS:0000000000000000 [ 843.876242] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 843.880778] CR2: 00007fa42affcfb8 CR3: 000000011433a002 CR4: 0000000000770ef0 [ 843.885336] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 843.889809] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 843.894229] PKRU: 55555554 [ 843.898539] Call Trace: [ 843.902772] <IRQ> [ 843.906922] ? __die_body+0x1e/0x60 [ 843.911032] ? die+0x3c/0x60 [ 843.915037] ? do_trap+0xe2/0x110 [ 843.918911] ? pskb_expand_head+0x2ac/0x300 [ 843.922687] ? do_error_trap+0x65/0x80 [ 843.926342] ? pskb_expand_head+0x2ac/0x300 [ 843.929905] ? exc_invalid_op+0x50/0x60 [ 843.933398] ? pskb_expand_head+0x2ac/0x300 [ 843.936835] ? asm_exc_invalid_op+0x1a/0x20 [ 843.940226] ? pskb_expand_head+0x2ac/0x300 [ 843.943580] inet_frag_reasm_prepare+0xd1/0x240 [ 843.946904] ip_defrag+0x5d4/0x870 [ 843.950132] nf_ct_handle_fragments+0xec/0x130 [nf_conntrack] [ 843.953334] tcf_ct_act+0x252/0xd90 [act_ct] [ 843.956473] ? tcf_mirred_act+0x516/0x5a0 [act_mirred] [ 843.959657] tcf_action_exec+0xa1/0x160 [ 843.962823] fl_classify+0x1db/0x1f0 [cls_flower] [ 843.966010] ? skb_clone+0x53/0xc0 [ 843.969173] tcf_classify+0x24d/0x420 [ 843.972333] tc_run+0x8f/0xf0 [ 843.975465] __netif_receive_skb_core+0x67a/0x1080 [ 843.978634] ? dev_gro_receive+0x249/0x730 [ 843.981759] __netif_receive_skb_list_core+0x12d/0x260 [ 843.984869] netif_receive_skb_list_internal+0x1cb/0x2f0 [ 843.987957] ? mlx5e_handle_rx_cqe_mpwrq_rep+0xfa/0x1a0 [mlx5_core] [ 843.991170] napi_complete_done+0x72/0x1a0 [ 843.994305] mlx5e_napi_poll+0x28c/0x6d0 [mlx5_core] [ 843.997501] __napi_poll+0x25/0x1b0 [ 844.000627] net_rx_action+0x256/0x330 [ 844.003705] __do_softirq+0xb3/0x29b [ 844.006718] irq_exit_rcu+0x9e/0xc0 [ 844.009672] common_interrupt+0x86/0xa0 [ 844.012537] </IRQ> [ 844.015285] <TASK> [ 844.017937] asm_common_interrupt+0x26/0x40 [ 844.020591] RIP: 0010:acpi_safe_halt+0x1b/0x20 [ 844.023247] Code: ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 65 48 8b 04 25 00 18 03 00 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 81 d0 44 00 fb ---truncated---
Why
The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.
What
In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ct: fix skb leak and crash on ooo frags act_ct adds skb->users before defragmentation. If frags arrive in order, the last frag's reference is reset in: inet_frag_reasm_prepare skb_morph which is not straightforward. However when frags arrive out of order, nobody unref the last frag, and all frags are leaked. The situation is even worse, as initiating packet capture can lead to a crash[0] when skb has been cloned and shared at the same time. Fix the issue by removing skb_get() before defragmentation. act_ct returns TC_ACT_CONSUMED when defrag failed or in progress. [0]: [ 843.804823] ------------[ cut here ]------------ [ 843.809659] kernel BUG at net/core/skbuff.c:2091! [ 843.814516] invalid opcode: 0000 [#1] PREEMPT SMP [ 843.819296] CPU: 7 PID: 0 Comm: swapper/7 Kdump: loaded Tainted: G S 6.7.0-rc3 #2 [ 843.824107] Hardware name: XFUSION 1288H V6/BC13MBSBD, BIOS 1.29 11/25/2022 [ 843.828953] RIP: 0010:pskb_expand_head+0x2ac/0x300 [ 843.833805] Code: 8b 70 28 48 85 f6 74 82 48 83 c6 08 bf 01 00 00 00 e8 38 bd ff ff 8b 83 c0 00 00 00 48 03 83 c8 00 00 00 e9 62 ff ff ff 0f 0b <0f> 0b e8 8d d0 ff ff e9 b3 fd ff ff 81 7c 24 14 40 01 00 00 4c 89 [ 843.843698] RSP: 0018:ffffc9000cce07c0 EFLAGS: 00010202 [ 843.848524] RAX: 0000000000000002 RBX: ffff88811a211d00 RCX: 0000000000000820 [ 843.853299] RDX: 0000000000000640 RSI: 0000000000000000 RDI: ffff88811a211d00 [ 843.857974] RBP: ffff888127d39518 R08: 00000000bee97314 R09: 0000000000000000 [ 843.862584] R10: 0000000000000000 R11: ffff8881109f0000 R12: 0000000000000880 [ 843.867147] R13: ffff888127d39580 R14: 0000000000000640 R15: ffff888170f7b900 [ 843.871680] FS: 0000000000000000(0000) GS:ffff889ffffc0000(0000) knlGS:0000000000000000 [ 843.876242] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 843.880778] CR2: 00007fa42affcfb8 CR3: 000000011433a002 CR4: 0000000000770ef0 [ 843.885336] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 843.889809] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 843.894229] PKRU: 55555554 [ 843.898539] Call Trace: [ 843.902772] <IRQ> [ 843.906922] ? __die_body+0x1e/0x60 [ 843.911032] ? die+0x3c/0x60 [ 843.915037] ? do_trap+0xe2/0x110 [ 843.918911] ? pskb_expand_head+0x2ac/0x300 [ 843.922687] ? do_error_trap+0x65/0x80 [ 843.926342] ? pskb_expand_head+0x2ac/0x300 [ 843.929905] ? exc_invalid_op+0x50/0x60 [ 843.933398] ? pskb_expand_head+0x2ac/0x300 [ 843.936835] ? asm_exc_invalid_op+0x1a/0x20 [ 843.940226] ? pskb_expand_head+0x2ac/0x300 [ 843.943580] inet_frag_reasm_prepare+0xd1/0x240 [ 843.946904] ip_defrag+0x5d4/0x870 [ 843.950132] nf_ct_handle_fragments+0xec/0x130 [nf_conntrack] [ 843.953334] tcf_ct_act+0x252/0xd90 [act_ct] [ 843.956473] ? tcf_mirred_act+0x516/0x5a0 [act_mirred] [ 843.959657] tcf_action_exec+0xa1/0x160 [ 843.962823] fl_classify+0x1db/0x1f0 [cls_flower] [ 843.966010] ? skb_clone+0x53/0xc0 [ 843.969173] tcf_classify+0x24d/0x420 [ 843.972333] tc_run+0x8f/0xf0 [ 843.975465] __netif_receive_skb_core+0x67a/0x1080 [ 843.978634] ? dev_gro_receive+0x249/0x730 [ 843.981759] __netif_receive_skb_list_core+0x12d/0x260 [ 843.984869] netif_receive_skb_list_internal+0x1cb/0x2f0 [ 843.987957] ? mlx5e_handle_rx_cqe_mpwrq_rep+0xfa/0x1a0 [mlx5_core] [ 843.991170] napi_complete_done+0x72/0x1a0 [ 843.994305] mlx5e_napi_poll+0x28c/0x6d0 [mlx5_core] [ 843.997501] __napi_poll+0x25/0x1b0 [ 844.000627] net_rx_action+0x256/0x330 [ 844.003705] __do_softirq+0xb3/0x29b [ 844.006718] irq_exit_rcu+0x9e/0xc0 [ 844.009672] common_interrupt+0x86/0xa0 [ 844.012537] </IRQ> [ 844.015285] <TASK> [ 844.017937] asm_common_interrupt+0x26/0x40 [ 844.020591] RIP: 0010:acpi_safe_halt+0x1b/0x20 [ 844.023247] Code: ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 65 48 8b 04 25 00 18 03 00 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 81 d0 44 00 fb ---truncated---
Why
The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Missing Release of Memory after Effective Lifetime → disrupt the affected service
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-401 ↗
CWE-401: Missing Release of Memory after Effective Lifetime. The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 18 Mar 2024 · Last source change 5 Aug 2026, 09:10 UTC · CWE-401 · Missing Release of Memory after Effective Lifetime
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2023-57234
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
NVD statusNVD modified after enrichment
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.