Linux Kernel up to 7.3-rc3 pppoatm pppoatm_send out-of-bounds

CVSS Meta Temp Score
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CTI Interest Score
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9.5$0-$5k0.55

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.3-rc3 and classified as very critical. Impacted is the function pppoatm_send of the component pppoatm. Executing a manipulation can lead to out-of-bounds. This vulnerability is handled as CVE-2026-98287. The attack can be executed remotely. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 7.3-rc3 and classified as very critical. This vulnerability affects the function pppoatm_send of the component pppoatm. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: pppoatm: ensure a writable skb header and linear data In pppoatm_send(), LLC encapsulation checks whether there is sufficient headroom for the 4-byte LLC header, but does not ensure that the skb header is writable. Normal transmit packets passing through ppp_start_xmit() have their header unshared via skb_cow_head(). However, packets can also reach pppoatm_send() via PPP channel bridging (PPPIOCBRIDGECHAN) without going through ppp_start_xmit(). Use skb_cow_head() to ensure both sufficient headroom and a writable header before pushing the LLC header. While at it: - Call pskb_may_pull(skb, 1) before inspecting skb->data[0] to prevent out-of-bounds reads on zero-length or non-linear frames (e.g. from bridging). - Defer SC_COMP_PROT protocol compression until after pppoatm_may_send() succeeds. This eliminates the temporary skb allocation on admission failure and completely removes the fragile "undo" heuristic at the nospace label, avoiding any risk of reading uninitialized headroom or performing an unbalanced skb_push().

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-98287 since 09/25/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/06/2026).

Upgrading to version 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.54, 7.2.8 or 7.3-rc4 eliminates this vulnerability. Applying the patch 208ccc4d08b1897451e9ba01c016bf93ff107966/e6cd1bba7d113c15c00ac63671213a096fe4d686/ffc448eb54f5ba80d4212c1e870cdb92b0f709fa/8e66c5969acd859ba72fb0a7fa895623fc1b3769/e2f5529b0016db7d34f411408607f5cf395a542e/30992fe39e65589ed8e000425e088fa74994b811/ecc7253683a3c55caa868ce0ee530fcb0044bd3c is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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Name

Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.15.222/6.1.189/6.6.158/6.12.112/6.18.54/7.2.8/7.3-rc4
Patch: 208ccc4d08b1897451e9ba01c016bf93ff107966/e6cd1bba7d113c15c00ac63671213a096fe4d686/ffc448eb54f5ba80d4212c1e870cdb92b0f709fa/8e66c5969acd859ba72fb0a7fa895623fc1b3769/e2f5529b0016db7d34f411408607f5cf395a542e/30992fe39e65589ed8e000425e088fa74994b811/ecc7253683a3c55caa868ce0ee530fcb0044bd3c

Timelineinfo

09/25/2026 CVE reserved
10/06/2026 +11 days Advisory disclosed
10/06/2026 +0 days VulDB entry created
10/06/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98287 (🔒)
GCVE (CVE): GCVE-0-2026-98287
GCVE (VulDB): GCVE-100-414166

Entryinfo

Created: 10/06/2026 13:20
Changes: 10/06/2026 13:20 (59)
Complete: 🔍
Cache ID: 216::103

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