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ReviewCritical

CVE-2026-74569

Linux

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_sip: widen NAT rewrite delta to s32 in sip_help_tcp() sip_help_tcp() stores the size change of each NAT-rewritten SIP message in s16 diff and accumulates it in s16 tdiff, but a single message can grow by more than S16_MAX while the packet stays under the 65535 enlarge_skb() limit: nf_nat_sip() rewrites every matching URI, and a long Contact list expands the message by tens of kilobytes. diff then wraps, and "datalen = datalen + diff - msglen" yields a huge unsigned datalen, so the next iteration's ct...

CVSS
9.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.08.15
PRIORITY ASSESSMENT

Review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 9.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_sip: widen NAT rewrite delta to s32 in sip_help_tcp() sip_help_tcp() stores the size change of each NAT-rewritten SIP message in s16 diff and accumulates it in s16 tdiff, but a single message can grow by more than S16_MAX while the packet stays under the 65535 enlarge_skb() limit: nf_nat_sip() rewrites every matching URI, and a long Contact list expands the message by tens of kilobytes. diff then wraps, and "datalen = datalen + diff - msglen" yields a huge unsigned datalen, so the next iteration's ct...

Affected product and versions

Product
Linux
Affected versions
>= f5b321bd37fbec9188feb1f721ab46a5ac0b35da < ed1f9be6dc8e2e280b8725e44ccdc6e0cd38640d, >= f5b321bd37fbec9188feb1f721ab46a5ac0b35da < 1b0843f9e9b9b0b9b4b70d143b67e58163c85b2c, >= f5b321bd37fbec9188feb1f721ab46a5ac0b35da < 32d4abc8923b0d4046fd63ad6e4917872e44eb6d, >= f5b321bd37fbec9188feb1f721ab46a5ac0b35da < 63eea41759fd682229c14e0a2205802b46d106f3, >= f5b321bd37fbec9188feb1f721ab46a5ac0b35da < c97621a110e386b2dd69e276eb699e1d3cec581d, >= f5b321bd37fbec9188feb1f721ab46a5ac0b35da < f74554e67ccf04d1fa71069e8c9afa2717e40716, >= f5b321bd37fbec9188feb1f721ab46a5ac0b35da < ef5e2c6555d2bb52dfe0e4053a8c6193f9d83b64, >= f5b321bd37fbec9188feb1f721ab46a5ac0b35da < db3d0e0e5d4bc5ab4fe445b9f413d1b486508ca5, >= 2.6.34
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
Not available