Medium 5.5Published Apr 22, 2026

CVE-2026-31518esp: fix skb leak with espintcp and async crypto

Updated under an hour ago (Oct 28, 2026, 3:00 PM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: esp: fix skb leak with espintcp and async crypto When the TX queue for espintcp is full, esp_output_tail_tcp will return an error and not free the skb, because with synchronous crypto, the common xfrm output code will drop the packet for us. With async crypto (esp_output_done), we need to drop the skb when esp_output_tail_tcp returns an error.

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 14, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 before aca3ad0c262f54a5b5c95dda80a48365997d1224; from e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 before 41aafca57de4a4c026701622bd4648f112a9edcd; from e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 before 4820847e036ff1035b01b69ad68dfc17e7028fe9; from e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 before 6a3ec6efbc4f90e0ccb2e71574f07351f19996f4; from e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 before df6f995358dc1f3c42484f5cfe241d7bd3e1cd15; from e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 before 88d386243ed374ac969dabd3bbc1409a31d81818; from e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 before 6aa9841d917532d0f2d932d1ff2f3a94305aaf47; from e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 before 0c0eef8ccd2413b0a10eb6bbd3442333b1e64dd2	CNA record
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
linux linux_kernel linux:linux_kernel	from 5.6 before 5.10.253; from 5.11 before 5.15.203; from 5.16 before 6.1.168; from 6.2 before 6.6.131; from 6.7 before 6.12.80; from 6.13 before 6.18.21; from 6.19 before 6.19.11; 7.0; and 6 more ranges	NVD

References

References

https://git.kernel.org/stable/c/aca3ad0c262f54a5b5c95dda80a48365997d1224	patch
https://git.kernel.org/stable/c/41aafca57de4a4c026701622bd4648f112a9edcd	patch
https://git.kernel.org/stable/c/4820847e036ff1035b01b69ad68dfc17e7028fe9	patch
https://git.kernel.org/stable/c/6a3ec6efbc4f90e0ccb2e71574f07351f19996f4	patch
https://git.kernel.org/stable/c/df6f995358dc1f3c42484f5cfe241d7bd3e1cd15	patch
https://git.kernel.org/stable/c/88d386243ed374ac969dabd3bbc1409a31d81818	patch
https://git.kernel.org/stable/c/6aa9841d917532d0f2d932d1ff2f3a94305aaf47	patch
https://git.kernel.org/stable/c/0c0eef8ccd2413b0a10eb6bbd3442333b1e64dd2	patch
https://cert-portal.siemens.com/productcert/html/ssa-019113.html
https://cert-portal.siemens.com/productcert/html/ssa-082556.html
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The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.