CVE-2026-80793
CVE.org · Published
- Record status
- Published
- Identifier year (not publication year)
- 2026
- Source publication
- Source updated
- Imported by cveboard
- Source snapshot
- cve_2026-10-24_midnight_baseline ·
CNA source text (English)
ipv4: reject undersized MTUs in ip_do_fragment()
In the Linux kernel, the following vulnerability has been resolved: ipv4: reject undersized MTUs in ip_do_fragment() ip_do_fragment() subtracts the IPv4 header length from the effective MTU and passes the resulting payload MTU to ip_frag_next(). If the effective MTU is smaller than hlen + 8, ip_frag_next() rounds the fragment payload length down to zero. The fragmentation state then never makes forward progress: state->left, state->ptr and state->offset stay unchanged while ip_do_fragment() keeps allocating and transmitting header-only fragments until the softlockup detector fires. This is reproducible with a route installed using "mtu lock 20", but it is also reproducible without route MTU lock, for example by forwarding a packet to a device whose MTU is 20. Fix it in ip_do_fragment() by rejecting mtu < hlen + 8 with -EMSGSIZE, matching the existing IPv6 fragmentation check.
Scoped product and version facts
Fix information unknown; no fixed version is derived here. Missing information does not prove that no fix exists.
Exploitation unknown; this catalogue does not assess exploitation.
Linux
- Vendor
- Linux
- Product
- Linux
- Platforms
- Unknown
- Default status
unaffected
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 | affected | git | a716a64a4ba68cd46f2745fba2b1099fe8e0aa59 | Unavailable | None listed |
| 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 | affected | git | 515b6816ba0c12d8415c88e5f41e6ec029e35cfa | Unavailable | None listed |
| 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 | affected | git | 74ce7389f8f562d39015f59a00ef7ad6acd37803 | Unavailable | None listed |
| 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 | affected | git | b0ea911453ce7210e8200a07a94d2458bd1e6430 | Unavailable | None listed |
| 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 | affected | git | 36e0741833bd823866f8cb9f112f37cea1a70b60 | Unavailable | None listed |
| 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 | affected | git | d9d1a676b033acabf8e5645f730486d1f8204a3f | Unavailable | None listed |
| 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 | affected | git | 3556beb8ca86677af2aca5bfbed6f8e790fccc83 | Unavailable | None listed |
| 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 | affected | git | c8a74adccaf028223054633b532593101dfcc581 | Unavailable | None listed |
| 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 | affected | git | c0726f0caf8c6b3208552949e17d23634a2f3129 | Unavailable | None listed |
Linux
- Vendor
- Linux
- Product
- Linux
- Platforms
- Unknown
- Default status
affected
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 2.6.12 | affected | Unavailable | Unavailable | Unavailable | None listed |
| 0 | unaffected | semver | 2.6.12 | Unavailable | None listed |
| 5.10.267 | unaffected | semver | Unavailable | 5.10.* | None listed |
| 5.15.218 | unaffected | semver | Unavailable | 5.15.* | None listed |
| 6.1.185 | unaffected | semver | Unavailable | 6.1.* | None listed |
| 6.6.154 | unaffected | semver | Unavailable | 6.6.* | None listed |
| 6.12.106 | unaffected | semver | Unavailable | 6.12.* | None listed |
| 6.18.47 | unaffected | semver | Unavailable | 6.18.* | None listed |
| 7.1.11 | unaffected | semver | Unavailable | 7.1.* | None listed |
| 7.2.1 | unaffected | semver | Unavailable | 7.2.* | None listed |
| 7.3 | unaffected | original_commit_for_fix | Unavailable | * | None listed |