CVE-2025-21758: linux
Vulnerability summary
CVE-2025-21758 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 17.06% chance of exploitation in the next 30 days, higher than 97% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 35 · Related 35Timeline
- 27-02-2025PublishedVulnerability first disclosed.
- 15-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: ipv6: mcast: add RCU protection to mld_newpack() mld_newpack() can be called without RTNL or RCU being held. Note that we no longer can use sock_alloc_send_skb() because ipv6.igmp_sk uses GFP_KERNEL allocations which can sleep. Instead use alloc_skb() and charge the net->ipv6.igmp_sk socket under RCU protection.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
- NVDNIST5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
EPSS trend
Probability
17.06%
Chance of exploitation in the next 30 days
Percentile
97%
Versus all other CVEs
30-day change
+3.36 pp
From 13.71% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Ubuntu137 products
- linuxAll versions (No fix recorded) | < 5.15.0-140.150 | < 6.8.0-78.78
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1084.91 | < 6.8.0-1035.37
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551, < 29fa42197f26a97cde29fa8c40beddf44ea5c8f3 | ≥ b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551, < e8af3632a7f2da83e27b083f787bced1faba00b1 | ≥ b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551, < 1b91c597b0214b1b462eb627ec02658c944623f2 | ≥ b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551, < 25195f9d5ffcc8079ad743a50c0409dbdc48d98a | ≥ b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551, < d60d493b0e65647e0335e6a7c4547abcea7df8e9 | ≥ b8ad0cbc58f703972e9e37c4e2a8081dd7e6a551, < a527750d877fd334de87eef81f1cb5f0f0ca3373 | 2.6.26
- linux_kernel≥ 2.6.26, < 5.15.179 | ≥ 5.16, < 6.1.129 | ≥ 6.2, < 6.6.79 | ≥ 6.7, < 6.12.16 | ≥ 6.13, < 6.13.4 | 6.14:rc1 | 6.14:rc2
Debian1 product
- linux< 6.1.129-1 | < 6.12.16-1
3 vendors · 140 products
