CVE-2024-49977 — net: stmmac: Fix zero-division error when disabling tc cbs
In the Linux kernel, the following vulnerability has been resolved: net: stmmac: Fix zero-division error when disabling tc cbs The commit b8c43360f6e4 ("net: stmmac: No need to calculate speed divider when offload is disabled") allows the "port_transmit_rate_kbps" to be set to a value of 0, which is then passed to the "div_s64" function when tc-cbs is disabled. This leads to a zero-division error. When tc-cbs is disabled, the idleslope, sendslope, and credit values the credit values are not required to be configured. Therefore, adding a return statement after setting the txQ mode to DCB when tc-cbs is disabled would prevent a zero-division error.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ a71b686418ee6bcb6d6365f7f6d838d9874d9c64 and < 03582f4752427f60817d896f1a827aff772bd31eversion 6.10≥ 6.9.7 and < 6.10≥ 6.6.36 and < 6.6.55≥ 6.1.96 and < 6.1.113≥ 5.15.162 and < 5.15.168≥ 5.10.221 and < 5.10.227version f01782804147a8c21f481b3342c83422c041d2c0 and 6 more≥ b8c43360f6e424131fa81d3ba8792ad8ff25a09e and < 675faf5a14c14a2be0b870db30a70764df81e2df≥ b8c43360f6e424131fa81d3ba8792ad8ff25a09e and < 837d9df9c0792902710149d1a5e0991520af0f93≥ b8c43360f6e424131fa81d3ba8792ad8ff25a09e and < e297a2bf56d12fd7f91a0c209eb6ea84361f3368≥ 521d42a1c24d638241220d4b9fa7e7a0ed02b88e and < 5d43e1ad4567d67af2b42d3ab7c14152ffed25c6≥ 2145583e5995598f50d66f8710c86bb1e910ac46 and < b0da9504a528f05f97d926b4db74ff21917a33e9≥ b4bca4722fda928810d024350493990de39f1e40 and < e33fe25b1efe4f2e6a5858786dbc82ae4c44ed4c |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel | ≥ 5.10.221 and < 5.10.227≥ 6.11 and < 6.11.3≥ 6.10 and < 6.10.14≥ 6.9.7 and < 6.10≥ 6.6.36 and < 6.6.55≥ 6.1.96 and < 6.1.113≥ 5.15.162 and < 5.15.168 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.5 | CVSS 3.1 | Medium | 1.8 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
| 5.5 | CVSS 3.1 | Medium | — | — | GitHub, Inc. via GitHub Security Advisories |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 5.5
- Source status changed · → Modified
- Record created in this database
- 2024
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
13 on the record
- git.kernel.org/stable/c/b0da9504a528f05f97d926b4db74ff21917a33e9
- git.kernel.org/stable/c/03582f4752427f60817d896f1a827aff772bd31e
- git.kernel.org/stable/c/837d9df9c0792902710149d1a5e0991520af0f93
- git.kernel.org/stable/c/5d43e1ad4567d67af2b42d3ab7c14152ffed25c6
- git.kernel.org/stable/c/675faf5a14c14a2be0b870db30a70764df81e2df
- git.kernel.org/stable/c/e297a2bf56d12fd7f91a0c209eb6ea84361f3368
- git.kernel.org/stable/c/e33fe25b1efe4f2e6a5858786dbc82ae4c44ed4c
- nvd.nist.gov/vuln/detail/CVE-2024-49977
- cert-portal.siemens.com/productcert/html/ssa-355557.html
- github.com/advisories/GHSA-8cpm-hmp4-fcm6
- lists.debian.org/debian-lts-announce/2025/03/msg00002.html
- cert-portal.siemens.com/productcert/html/ssa-265688.html
- lists.debian.org/debian-lts-announce/2025/01/msg00001.html
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 15h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 15h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2024-49977 is "net: stmmac: Fix zero-division error when disabling tc cbs", rated Medium. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. EPSS 0.25% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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