CVE-2023-53500

HIGHNVD 7.87.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2025-10-01. NVD baseline CVSS 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 3 sources updated this week

Also known asEUVD-2025-32765 (ENISA EUVD) · GHSA-hx6j-r6x5-73w3 (GitHub Security Advisories)Source: ENISA EUVD

7.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

xfrm: fix slab-use-after-free in decode_session6

When the xfrm device is set to the qdisc of the sfb type, the cb field of the sent skb may be modified during enqueuing. Then, slab-use-after-free may occur when the xfrm device sends IPv6 packets.

The stack information is as follows: BUG: KASAN: slab-use-after-free in decode_session6+0x103f/0x1890 Read of size 1 at addr ffff8881111458ef by task swapper/3/0 CPU: 3 PID: 0 Comm: swapper/3 Not tainted 6.4.0-next-20230707 #409 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014 Call Trace:

dump_stack_lvl+0xd9/0x150 print_address_description.constprop.0+0x2c/0x3c0 kasan_report+0x11d/0x130 decode_session6+0x103f/0x1890 __xfrm_decode_session+0x54/0xb0 xfrmi_xmit+0x173/0x1ca0 dev_hard_start_xmit+0x187/0x700 sch_direct_xmit+0x1a3/0xc30 __qdisc_run+0x510/0x17a0 __dev_queue_xmit+0x2215/0x3b10 neigh_connected_output+0x3c2/0x550 ip6_finish_output2+0x55a/0x1550 ip6_finish_output+0x6b9/0x1270 ip6_output+0x1f1/0x540 ndisc_send_skb+0xa63/0x1890 ndisc_send_rs+0x132/0x6f0 addrconf_rs_timer+0x3f1/0x870 call_timer_fn+0x1a0/0x580 expire_timers+0x29b/0x4b0 run_timer_softirq+0x326/0x910 __do_softirq+0x1d4/0x905 irq_exit_rcu+0xb7/0x120 sysvec_apic_timer_interrupt+0x97/0xc0

asm_sysvec_apic_timer_interrupt+0x1a/0x20 RIP: 0010:intel_idle_hlt+0x23/0x30 Code: 1f 84 00 00 00 00 00 f3 0f 1e fa 41 54 41 89 d4 0f 1f 44 00 00 66 90 0f 1f 44 00 00 0f 00 2d c4 9f ab 00 0f 1f 44 00 00 fb f4 44 89 e0 41 5c c3 66 0f 1f 44 00 00 f3 0f 1e fa 41 54 41 89 d4 RSP: 0018:ffffc90000197d78 EFLAGS: 00000246 RAX: 00000000000a83c3 RBX: ffffe8ffffd09c50 RCX: ffffffff8a22d8e5 RDX: 0000000000000001 RSI: ffffffff8d3f8080 RDI: ffffe8ffffd09c50 RBP: ffffffff8d3f8080 R08: 0000000000000001 R09: ffffed1026ba6d9d R10: ffff888135d36ceb R11: 0000000000000001 R12: 0000000000000001 R13: ffffffff8d3f8100 R14: 0000000000000001 R15: 0000000000000000 cpuidle_enter_state+0xd3/0x6f0 cpuidle_enter+0x4e/0xa0 do_idle+0x2fe/0x3c0 cpu_startup_entry+0x18/0x20 start_secondary+0x200/0x290 secondary_startup_64_no_verify+0x167/0x16b

Allocated by task 939: kasan_save_stack+0x22/0x40 kasan_set_track+0x25/0x30 __kasan_slab_alloc+0x7f/0x90 kmem_cache_alloc_node+0x1cd/0x410 kmalloc_reserve+0x165/0x270 __alloc_skb+0x129/0x330 inet6_ifa_notify+0x118/0x230 __ipv6_ifa_notify+0x177/0xbe0 addrconf_dad_completed+0x133/0xe00 addrconf_dad_work+0x764/0x1390 process_one_work+0xa32/0x16f0 worker_thread+0x67d/0x10c0 kthread+0x344/0x440 ret_from_fork+0x1f/0x30 The buggy address belongs to the object at ffff888111145800 which belongs to the cache skbuff_small_head of size 640 The buggy address is located 239 bytes inside of freed 640-byte region [ffff888111145800, ffff888111145a80)

As commit f855691975bb ("xfrm6: Fix the nexthdr offset in _decode_session6.") showed, xfrm_decode_session was originally intended only for the receive path. IP6CB(skb)->nhoff is not set during transmission. Therefore, set the cb field in the skb to 0 before sending packets.

CVSS v3
7.8
EG Score
7.8HIGHmedium confidence
EG Risk
35
EG Risk 35/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity78% × 45%
Impact severity (EG Severity): CVSS 7.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
5th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.

EG Severity
7.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-29). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

October 1, 2025

Last Modified

October 15, 2026

Advisory Details (7)

Auto-updated Aug 5, 2026
Patch available.
Web page

xfrm: fix slab-use-after-free in decode_session6 - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/53223f2ed1ef5c90dad814daaaefea4e68a933c8
Web page

xfrm: fix slab-use-after-free in decode_session6 - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/86f15300a22656db3fa8c8967defbcd24fac4d37
Web page

xfrm: fix slab-use-after-free in decode_session6 - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0d27567fde5be5f0edc2db5c110142b7915b8fa8
Web page

xfrm: fix slab-use-after-free in decode_session6 - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/44b3d40967009304617a7a6486490c1d6c12f899
Web page

xfrm: fix slab-use-after-free in decode_session6 - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/bafa236380816b41b2c4c6970d9067fefa4a6c9e
Web page

xfrm: fix slab-use-after-free in decode_session6 - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/db0e50741f0387f388e9ec824ea7ae8456554d5b
Web page

xfrm: fix slab-use-after-free in decode_session6 - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/da4cbaa75ed088b6d70db77b9103a27e2359e243

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
linuxKernel @ 4.19.293 (fixes >=3.19.0)—osv

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
linux5.10.103-1 ... 5.10.92-2 (34 versions)
  • every version up to 5.10.197-1: fixed in 5.10.197-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.27-1 ... 6.1.38-4~bpo11+1 (8 versions)
  • every version up to 6.1.52-1: fixed in 6.1.52-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 6.4.13-1: fixed in 6.4.13-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux—
  • every version up to 6.4.13-1: fixed in 6.4.13-1
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 40× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 93 of 200 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 7 repeat rows among the latest 100 are merged into the row they repeat. The 107 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:40 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  2. 2026-11-01 16:31 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  3. 2026-10-31 16:30 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  4. 2026-10-30 16:31 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  5. 2026-10-29 22:59 UTCEG score recompute
  6. 2026-10-29 22:59 UTCGHSA enrichmentGHSA-hx6j-r6x5-73w3 · GitHub severity HIGH · GitHub CVSS 7.8
  7. 2026-10-29 16:30 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  8. 2026-10-28 16:29 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  9. 2026-10-26 16:29 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  10. 2026-10-25 17:28 UTCEG score recompute
  11. 2026-10-25 16:30 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  12. 2026-10-24 16:29 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  13. 2026-10-23 16:29 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  14. 2026-10-22 22:48 UTCEG score recompute
  15. 2026-10-22 22:48 UTCGHSA enrichmentGHSA-hx6j-r6x5-73w3 · GitHub severity HIGH · GitHub CVSS 7.8
  16. 2026-10-22 16:31 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  17. 2026-10-21 16:29 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  18. 2026-10-20 16:30 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  19. 2026-10-19 16:29 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  20. 2026-10-18 16:29 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  21. 2026-10-18 07:40 UTCEG score recompute
  22. 2026-10-17 16:30 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  23. 2026-10-16 16:36 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  24. 2026-10-15 22:38 UTCGHSA enrichmentGHSA-hx6j-r6x5-73w3 · GitHub severity HIGH · GitHub CVSS 7.8
  25. 2026-10-15 21:57 UTCEG score recompute
Show 68 more
  1. 2026-10-15 21:57 UTCGHSA enrichmentGHSA-hx6j-r6x5-73w3 · GitHub severity HIGH · GitHub CVSS 7.8
  2. 2026-10-15 16:29 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  3. 2026-10-14 16:30 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  4. 2026-10-13 16:30 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  5. 2026-10-12 18:12 UTCEG score recompute
  6. 2026-10-12 16:31 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  7. 2026-10-11 21:37 UTCEG score recompute
  8. 2026-10-11 13:45 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  9. 2026-10-10 19:58 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  10. 2026-10-09 20:05 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  11. 2026-10-08 17:06 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  12. 2026-10-07 23:46 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  13. 2026-10-06 15:15 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  14. 2026-10-05 17:41 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  15. 2026-10-04 23:20 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  16. 2026-10-01 19:48 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  17. 2026-09-30 16:37 UTCEG score recompute
  18. 2026-09-30 15:01 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  19. 2026-09-29 15:17 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  20. 2026-09-28 13:49 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  21. 2026-09-26 20:42 UTCOSV refresh
  22. 2026-09-26 00:22 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  23. 2026-09-24 14:01 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  24. 2026-09-23 13:46 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  25. 2026-09-20 20:14 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  26. 2026-09-18 19:26 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  27. 2026-09-16 14:06 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  28. 2026-09-16 05:11 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  29. 2026-09-15 03:08 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  30. 2026-09-13 16:45 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  31. 2026-09-12 14:58 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  32. 2026-09-11 14:51 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  33. 2026-09-11 09:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  34. 2026-09-08 21:58 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  35. 2026-09-07 15:59 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  36. 2026-09-07 06:47 UTCOSV refresh
  37. 2026-09-06 13:46 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  38. 2026-09-05 15:26 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  39. 2026-09-04 13:58 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  40. 2026-09-04 05:04 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  41. 2026-09-02 14:10 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  42. 2026-09-01 13:52 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  43. 2026-09-01 04:36 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  44. 2026-08-30 19:15 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  45. 2026-08-30 01:20 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  46. 2026-08-28 21:39 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  47. 2026-08-27 14:23 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  48. 2026-08-26 14:44 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  49. 2026-08-25 13:47 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  50. 2026-08-23 00:17 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  51. 2026-08-21 23:47 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  52. 2026-08-20 22:53 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  53. 2026-08-20 16:01 UTCOSV refresh
  54. 2026-08-19 17:02 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  55. 2026-08-18 13:46 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  56. 2026-08-16 14:54 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  57. 2026-08-16 02:12 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  58. 2026-08-15 01:28 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  59. 2026-08-13 21:58 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  60. 2026-08-12 13:49 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  61. 2026-08-10 23:58 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  62. 2026-08-09 13:44 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  63. 2026-08-07 16:25 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  64. 2026-08-06 13:45 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  65. 2026-08-05 19:15 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  66. 2026-08-05 10:19 UTCEG score recompute
  67. 2026-08-05 10:18 UTCGHSA enrichmentGHSA-hx6j-r6x5-73w3 · GitHub severity HIGH · GitHub CVSS 7.8
  68. 2026-08-04 10:57 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2023-53500?
CVE-2023-53500 is a high-severity vulnerability; its CVE record was published on October 1, 2025. In the Linux kernel, the following vulnerability has been resolved: xfrm: fix slab-use-after-free in decode_session6 When the xfrm device is set to the qdisc of the sfb type, the cb field of the sent skb may be modified during enqueuing. Then, slab-use-after-free may occur when the xfrm device…
When was the CVE record for CVE-2023-53500 published?
The CVE record for CVE-2023-53500 was published on October 1, 2025. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 15, 2026; the record at its source may have been updated since.
Is CVE-2023-53500 actively exploited?
CVE-2023-53500 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (5th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2023-53500?
CVE-2023-53500 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2023-53500?
A fix for CVE-2023-53500 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2023-53500

Explore →

Is Your Infrastructure Affected by CVE-2023-53500?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs