Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-63984— ipv6: rpl: fix hdrlen overflow in ipv6_rpl_srh_decompress()

CVSS 9.8 · Critical EPSS 0.52% · P41

Possible ATT&CK Techniques 1AI

T1190 · Exploit Public-Facing Application

Affected Version Matrix 18

VendorProductVersion RangeStatus
LinuxLinux8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3< 75b3680047bf09af8e7e471a7a6ddf2ce5847f56affected
8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3< fd238c51b0fa5390cceca9f1ac5a9ffda8063eedaffected
8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3< 3618b34942b76471d044369bfd30d58c39068bf1affected
8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3< 97e06791368c01f0ad2a4b3269c2abe19485ca32affected
8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3< de02fc049352af5a9595f015511222d0a85c326baffected
8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3< 6fe1cb312038516cb4d9fa089d700af7059f1a64affected
8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3< c0487a9c1e116cf349e2d1f302d9019670460858affected
8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3< 9d5e7a46a9f6d8f503b41bfefef70659845f1679affected
… +10 more rows
Get alerts for future matching vulnerabilitiesLog in to subscribe

I. Basic Information for CVE-2026-63984

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
ipv6: rpl: fix hdrlen overflow in ipv6_rpl_srh_decompress()
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: ipv6: rpl: fix hdrlen overflow in ipv6_rpl_srh_decompress() ipv6_rpl_srh_decompress() computes: outhdr->hdrlen = (((n + 1) * sizeof(struct in6_addr)) >> 3); hdrlen is __u8. For n >= 127 the result exceeds 255 and silently truncates. With n=127 (cmpri=15, cmpre=15, pad=0, hdrlen=16): (128 * 16) >> 3 = 256, truncated to 0 as __u8 The caller in ipv6_rpl_srh_rcv() then places the compressed header at buf + ((ohdr->hdrlen + 1) << 3). With hdrlen=0 this is buf + 8, but the decompressed region occupies buf[0..2055] (8-byte header plus 128 full addresses). The compressed header overlaps the decompressed data, and ipv6_rpl_srh_compress() writes into this overlap, corrupting the routing header of the forwarded packet. The existing guard at exthdrs.c:546 checks (n + 1) > 255, which prevents n+1 from overflowing unsigned char (the segments_left field), but does not prevent the computed hdrlen from overflowing __u8. n=127 passes because 128 <= 255, yet hdrlen=256 does not fit. Tighten the bound to (n + 1) > 127. This caps n at 126, giving hdrlen = (127 * 16) >> 3 = 254, which fits in __u8. The compressed header then lands at buf + ((254 + 1) << 3) = buf + 2040, exactly past the decompressed region (buf[0..2039]). No overlap. 127 segments is well beyond any realistic RPL deployment.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会开源的一款操作系统内核。 Linux kernel存在安全漏洞，该漏洞源于ipv6_rpl_srh_decompress()函数中hdrlen溢出，可能导致路由头损坏。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

VendorProductAffected VersionsCPESubscribe
LinuxLinux 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 ~ 75b3680047bf09af8e7e471a7a6ddf2ce5847f56 -
LinuxLinux 5.7 -

II. Public POCs for CVE-2026-63984

#POC DescriptionSource LinkShenlong Link
AI-Generated POCPremium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-63984

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-63984 (8)

Same Patch Batch · Linux · 2026-07-19 · 431 CVEs total

CVE-2026-6379510.0 CRITICAL9p: avoid putting oldfid in p9_client_walk() error path
CVE-2026-641229.8 CRITICALnet/mlx5e: Fix use-after-free in mlx5e_tx_reporter_timeout_recover
CVE-2026-640009.8 CRITICALnet: hsr: fix potential OOB access in supervision frame handling
CVE-2026-641509.8 CRITICALnetfilter: nft_inner: release local_lock before re-enabling softirqs
CVE-2026-639229.8 CRITICALipv6: exthdrs: refresh nh after handling HAO option
CVE-2026-639249.8 CRITICALipv6: exthdrs: refresh nh pointer after ipv6_hop_jumbo()
CVE-2026-640469.8 CRITICALnet: tls: prevent chain-after-chain in plain text SG
CVE-2026-640479.8 CRITICALnet: tls: fix off-by-one in sg_chain entry count for wrapped sk_msg ring
CVE-2026-639949.8 CRITICALtunnels: load network headers after skb_cow() in iptunnel_pmtud_build_icmp[v6]()
CVE-2026-641429.8 CRITICALksmbd: close durable scavenger races against m_fp_list lookups
CVE-2026-639939.8 CRITICALvxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()
CVE-2026-640559.8 CRITICALnet: ethernet: cortina: Carry over frag counter
CVE-2026-641369.8 CRITICALsmb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked()
CVE-2026-641329.8 CRITICALipv6: ioam: refresh hdr pointer before ioam6_event()
CVE-2026-533999.8 CRITICALnfsd: release layout stid on setlease failure
CVE-2026-641259.8 CRITICALnet: bcmgenet: keep RBUF EEE/PM disabled
CVE-2026-640569.8 CRITICALnet: ethernet: cortina: Make RX SKB per-port
CVE-2026-638009.8 CRITICALpNFS: Fix use-after-free in pnfs_update_layout()
CVE-2026-639789.8 CRITICALnet/handshake: Drain pending requests at net namespace exit
CVE-2026-638579.8 CRITICALnet: airoha: Do not read uninitialized fragment address in airoha_dev_xmit()

Showing top 20 of 431 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-63984

No comments yet

Leave a comment