5.5

CVE-2025-71098: ip6_gre: make ip6gre_header() robust

Modified
AliasesUBUNTU-CVE-2025-71098DEBIAN-CVE-2025-71098
Published 13-01-2026Last modified 19-10-2026

Vulnerability summary

CVE-2025-71098 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.14% chance of exploitation in the next 30 days, higher than 3.4% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.14%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 47 · Related 43
DLA-4475-1DLA-4476-1DSA-6126-1DSA-6127-1MGASA-2026-0017MGASA-2026-0018

Timeline

  1. 13-01-2026
    PublishedVulnerability first disclosed.
  2. 19-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: ip6_gre: make ip6gre_header() robust Over the years, syzbot found many ways to crash the kernel in ip6gre_header() [1]. This involves team or bonding drivers ability to dynamically change their dev->needed_headroom and/or dev->hard_header_len In this particular crash mld_newpack() allocated an skb with a too small reserve/headroom, and by the time mld_sendpack() was called, syzbot managed to attach an ip6gre device. [1] skbuff: skb_under_panic: text:ffffffff8a1d69a8 len:136 put:40 head:ffff888059bc7000 data:ffff888059bc6fe8 tail:0x70 end:0x6c0 dev:team0 ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:213 ! <TASK> skb_under_panic net/core/skbuff.c:223 [inline] skb_push+0xc3/0xe0 net/core/skbuff.c:2641 ip6gre_header+0xc8/0x790 net/ipv6/ip6_gre.c:1371 dev_hard_header include/linux/netdevice.h:3436 [inline] neigh_connected_output+0x286/0x460 net/core/neighbour.c:1618 neigh_output include/net/neighbour.h:556 [inline] ip6_finish_output2+0xfb3/0x1480 net/ipv6/ip6_output.c:136 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:220 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247 NF_HOOK+0x9e/0x380 include/linux/netfilter.h:318 mld_sendpack+0x8d4/0xe60 net/ipv6/mcast.c:1855 mld_send_cr net/ipv6/mcast.c:2154 [inline] mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.14%

Chance of exploitation in the next 30 days

Percentile

3%

Versus all other CVEs

30-day change

Increase +0.01 pp

From 0.13% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu157 products
  • linuxAll versions (No fix recorded) | < 5.15.0-173.183 | < 6.8.0-110.110 | < 6.17.0-22.22
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1103.110 | < 6.8.0-1052.55 | < 6.17.0-1012.12
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ c12b395a46646bab69089ce7016ac78177f6001f, < 17e7386234f740f3e7d5e58a47b5847ea34c3bc2 | ≥ c12b395a46646bab69089ce7016ac78177f6001f, < 41a1a3140aff295dee8063906f70a514548105e8 | ≥ c12b395a46646bab69089ce7016ac78177f6001f, < adee129db814474f2f81207bd182bf343832a52e | ≥ c12b395a46646bab69089ce7016ac78177f6001f, < 1717357007db150c2d703f13f5695460e960f26c | ≥ c12b395a46646bab69089ce7016ac78177f6001f, < 5fe210533e3459197eabfdbf97327dacbdc04d60 | ≥ c12b395a46646bab69089ce7016ac78177f6001f, < 91a2b25be07ce1a7549ceebbe82017551d2eec92 | ≥ c12b395a46646bab69089ce7016ac78177f6001f, < db5b4e39c4e63700c68a7e65fc4e1f1375273476 | 3.7
  • linux_kernel≥ 3.7.1, < 5.10.248 | ≥ 5.11, < 5.15.198 | ≥ 5.16, < 6.1.160 | ≥ 6.2, < 6.6.120 | ≥ 6.7, < 6.12.64 | ≥ 6.13, < 6.18.4 | 3.7 | 6.19:rc1 | 6.19:rc2 | 6.19:rc3 | 6.19:rc4 | 6.19:rc5 | 6.19:rc6 | 6.19:rc7 | 6.19:rc8
Debian1 product
  • linux< 6.1.162-1 | < 6.12.69-1 | < 6.18.5-1

3 vendors · 160 products

References

44 links
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