7.8

CVE-2020-36791: net_sched: keep alloc_hash updated after hash allocation

Modified
AliasesUBUNTU-CVE-2020-36791DEBIAN-CVE-2020-36791
Published 07-05-2025Last modified 05-08-2026

Vulnerability summary

CVE-2020-36791 is a high (CVSS 7.8) Out-of-bounds Read vulnerability in linux. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 9.7% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.20%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 3 · Related 3
SUSE-SU-2025:01982-1SUSE-SU-2025:01983-1SUSE-SU-2025:01995-1

Timeline

  1. 07-05-2025
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: net_sched: keep alloc_hash updated after hash allocation In commit 599be01ee567 ("net_sched: fix an OOB access in cls_tcindex") I moved cp->hash calculation before the first tcindex_alloc_perfect_hash(), but cp->alloc_hash is left untouched. This difference could lead to another out of bound access. cp->alloc_hash should always be the size allocated, we should update it after this tcindex_alloc_perfect_hash().

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.20%

Chance of exploitation in the next 30 days

Percentile

10%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.20% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu84 products
  • linux< 4.4.0-179.209 | < 4.15.0-99.100
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 4.4.0-1067.71 | < 4.4.0-1107.118 | < 4.15.0-1066.70
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 73c29d2f6f8ae731b1e09051b69ed3ba2319482b, < d6cdc5bb19b595486fb2e6661e5138d73a57f454 | ≥ b974ac51f5834a729de252fc5c1c9de9efd79b45, < c4453d2833671e3a9f6bd52f0f581056c3736386 | ≥ 6cb448ee493c8a514c9afa0c346f3f5b3227de85, < 9f8b6c44be178c2498a00b270872a6e30e7c8266 | ≥ 478c4b2ffd44e5186c7e22ae7c38a86a5b9cfde5, < 557d015ffb27b672e24e6ad141fd887783871dc2 | ≥ dd8142a6fa5270783d415292ec8169f4ea2a5468, < d23faf32e577922b6da20bf3740625c1105381bf | ≥ 2c66ff8d08f81bcf8e8cb22e31e39c051b15336a, < bd3ee8fb6371b45c71c9345cc359b94da2ddefa9 | ≥ 599be01ee567b61f4471ee8078870847d0a11e8e, < 0d1c3530e1bd38382edef72591b78e877e0edcd3 | ≥ 4.4.214, < 4.4.218 | ≥ 4.9.214, < 4.9.218 | ≥ 4.14.171, < 4.14.175 | ≥ 4.19.103, < 4.19.114 | ≥ 5.4.19, < 5.4.29 | ≥ 5.5.3, < 5.5.14
  • linux_kernel≥ 4.4.214, < 4.4.218 | ≥ 4.9.214, < 4.9.218 | ≥ 4.14.171, < 4.14.175 | ≥ 4.19.103, < 4.19.114 | ≥ 5.4.19, < 5.4.29 | ≥ 5.5.3, < 5.5.14 | 5.6:rc1 | 5.6:rc2 | 5.6:rc3 | 5.6:rc4 | 5.6:rc5 | 5.6:rc6 | 5.6:rc7
Debian1 product
  • linux< 5.5.17-1

3 vendors · 87 products

References

13 links
Show all 13 references