CVE-2026-23277

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.5 under NVD CVSS v3. EPSS exploit probability: 0.1%, top 98% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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

net/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit

teql_master_xmit() calls netdev_start_xmit(skb, slave) to transmit through slave devices, but does not update skb->dev to the slave device beforehand.

When a gretap tunnel is a TEQL slave, the transmit path reaches iptunnel_xmit() which saves dev = skb->dev (still pointing to teql0 master) and later calls iptunnel_xmit_stats(dev, pkt_len). This function does:

get_cpu_ptr(dev->tstats)

Since teql_master_setup() does not set dev->pcpu_stat_type to NETDEV_PCPU_STAT_TSTATS, the core network stack never allocates tstats for teql0, so dev->tstats is NULL. get_cpu_ptr(NULL) computes NULL + __per_cpu_offset[cpu], resulting in a page fault.

BUG: unable to handle page fault for address: ffff8880e6659018 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 68bc067 P4D 68bc067 PUD 0 Oops: Oops: 0002 [#1] SMP KASAN PTI RIP: 0010:iptunnel_xmit (./include/net/ip_tunnels.h:664 net/ipv4/ip_tunnel_core.c:89) Call Trace: ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847) __gre_xmit (net/ipv4/ip_gre.c:478) gre_tap_xmit (net/ipv4/ip_gre.c:779) teql_master_xmit (net/sched/sch_teql.c:319) dev_hard_start_xmit (net/core/dev.c:3887) sch_direct_xmit (net/sched/sch_generic.c:347) __dev_queue_xmit (net/core/dev.c:4802) neigh_direct_output (net/core/neighbour.c:1660) ip_finish_output2 (net/ipv4/ip_output.c:237) __ip_finish_output.part.0 (net/ipv4/ip_output.c:315) ip_mc_output (net/ipv4/ip_output.c:369) ip_send_skb (net/ipv4/ip_output.c:1508) udp_send_skb (net/ipv4/udp.c:1195) udp_sendmsg (net/ipv4/udp.c:1485) inet_sendmsg (net/ipv4/af_inet.c:859) __sys_sendto (net/socket.c:2206)

Fix this by setting skb->dev = slave before calling netdev_start_xmit(), so that tunnel xmit functions see the correct slave device with properly allocated tstats.

CVSS v3
5.5
EG Score
5.5(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity55% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
2%
KEV
Not listed

Published

March 20, 2026

Last Modified

July 14, 2026

Advisory Details (10)

Auto-updated Jul 17, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic🔴 Active Exploitation

SSA-082556

https://cert-portal.siemens.com/productcert/html/ssa-082556.html
generic

SSA-019113

https://cert-portal.siemens.com/productcert/html/ssa-019113.html
generic

net/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/81a43e8005366f16e629d8c95dfe05beaa8d36a7
generic

net/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6b1f563d670162e188a0f2aec39c24b67b106e17
generic

net/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/59b06d8b9bdb6b64b3c534c18da68bce5ccd31be
generic

net/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/57c153249143333bbf4ecf927bdf8aa2696ee397
generic

net/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/383493b9940e3d1b5517424081b3e072e20ec43c
generic

net/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/21ea283c2750c8307aa35ee832b0951cc993c27d
generic

net/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0cc0c2e661af418bbf7074179ea5cfffc0a5c466
generic

net/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0bad9c86edd22dec4df83c2b29872d66fd8a2ff4

Vendor Advisories for CVE-2026-23277(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
linuxKernel @ 5.10.253—osv
linuxKernel @ 6.1.167—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.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 1× in last 7d / 41× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

Showing the most recent 100 of 134 total refreshes for this CVE.

  1. 2026-07-30 01:30 UTCEPSS rescore
  2. 2026-07-24 14:17 UTCEPSS rescore
  3. 2026-07-23 14:18 UTCEPSS rescore
  4. 2026-07-23 14:18 UTCEPSS rescore
  5. 2026-07-23 03:06 UTCEG score recompute
  6. 2026-07-22 14:08 UTCEPSS rescore
  7. 2026-07-21 15:24 UTCEPSS rescore
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  9. 2026-07-20 17:08 UTCEPSS rescore
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  14. 2026-07-18 10:04 UTCEPSS rescore
  15. 2026-07-18 10:04 UTCEPSS rescore
  16. 2026-07-17 07:46 UTCOSV refresh
  17. 2026-07-16 17:03 UTCEPSS rescore
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  19. 2026-07-15 16:57 UTCEPSS rescore
  20. 2026-07-15 16:57 UTCEPSS rescore
  21. 2026-07-15 02:00 UTCEPSS rescore
  22. 2026-07-15 02:00 UTCEPSS rescore
  23. 2026-07-14 13:19 UTCNVD updateCVSS v3 → 5.5 · severity → MEDIUM
  24. 2026-07-14 13:11 UTCMITRE cvelistV5
  25. 2026-07-13 22:30 UTCEPSS rescore
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  1. 2026-07-13 06:13 UTCEPSS rescore
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  5. 2026-07-11 08:27 UTCEPSS rescore
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  9. 2026-07-07 13:46 UTCEPSS rescore
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  12. 2026-07-06 02:23 UTCEPSS rescore
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  14. 2026-07-05 02:30 UTCEPSS rescore
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  21. 2026-06-29 14:06 UTCEPSS rescore
  22. 2026-06-29 06:02 UTCOSV refresh
  23. 2026-06-28 14:07 UTCEPSS rescore
  24. 2026-06-28 14:07 UTCEPSS rescore
  25. 2026-06-28 04:56 UTCEPSS rescore
  26. 2026-06-28 04:56 UTCEPSS rescore
  27. 2026-06-27 03:08 UTCEPSS rescore
  28. 2026-06-25 13:49 UTCEPSS rescore
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  30. 2026-06-23 21:33 UTCEPSS rescore
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  32. 2026-06-22 14:25 UTCEPSS rescore
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  36. 2026-06-21 01:59 UTCEPSS rescore
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  38. 2026-06-19 19:25 UTCEPSS rescore
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  40. 2026-06-18 17:52 UTCEPSS rescore
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  43. 2026-06-16 17:52 UTCEPSS rescore
  44. 2026-06-15 17:48 UTCEPSS rescore
  45. 2026-06-14 23:18 UTCEPSS rescore
  46. 2026-06-13 23:00 UTCEPSS rescore
  47. 2026-06-13 23:00 UTCEPSS rescore
  48. 2026-06-12 23:12 UTCEPSS rescore
  49. 2026-06-11 23:42 UTCVendor advisory
  50. 2026-06-11 23:42 UTCGHSA enrichment
  51. 2026-06-11 14:00 UTCEPSS rescore
  52. 2026-06-10 22:18 UTCEPSS rescore
  53. 2026-06-10 17:40 UTCVendor advisory
  54. 2026-06-10 17:40 UTCGHSA enrichment
  55. 2026-06-10 13:22 UTCEPSS rescore
  56. 2026-06-09 16:28 UTCVendor advisory
  57. 2026-06-09 16:28 UTCGHSA enrichment
  58. 2026-06-08 14:17 UTCEPSS rescore
  59. 2026-06-08 14:17 UTCEPSS rescore
  60. 2026-06-07 15:25 UTCEPSS rescore
  61. 2026-06-07 15:24 UTCEPSS rescore
  62. 2026-06-07 14:17 UTCEG score recompute▲ 5.50
  63. 2026-06-07 14:17 UTCVendor advisory
  64. 2026-06-07 14:17 UTCGHSA enrichment
  65. 2026-06-06 13:47 UTCEPSS rescore
  66. 2026-06-06 13:47 UTCEPSS rescore
  67. 2026-06-06 13:47 UTCEPSS rescore
  68. 2026-06-05 22:47 UTCEPSS rescore
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  71. 2026-06-04 13:12 UTCEPSS rescore
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  74. 2026-06-02 20:13 UTCEPSS rescore
  75. 2026-06-02 20:13 UTCEPSS rescore

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Frequently asked(5)

What is CVE-2026-23277?
CVE-2026-23277 is a medium vulnerability published on March 20, 2026. In the Linux kernel, the following vulnerability has been resolved: net/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit teqlmasterxmit() calls netdevstartxmit(skb, slave) to transmit through slave devices, but does not update skb->dev to the slave device beforehand.…
When was CVE-2026-23277 disclosed?
CVE-2026-23277 was first published in the National Vulnerability Database on March 20, 2026, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-23277 actively exploited?
CVE-2026-23277 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 97.6% of all scored CVEs.
What is the CVSS score of CVE-2026-23277?
CVE-2026-23277 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-23277?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-23277, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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