9.8

CVE-2025-37879: 9p/net: fix improper handling of bogus negative read/write replies

Modified
AliasesUBUNTU-CVE-2025-37879DEBIAN-CVE-2025-37879
Published 09-05-2025Last modified 05-08-2026

Vulnerability summary

CVE-2025-37879 is a critical (CVSS 9.8) Out-of-bounds Read vulnerability in debian debian_linux. EPSS estimates a 0.72% chance of exploitation in the next 30 days, higher than 53.8% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 9.8 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.72%
0%100%
Low · +0.03 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 34 · Related 31
DLA-4193-1MGASA-2025-0182MGASA-2025-0183SUSE-SU-2025:01919-1SUSE-SU-2025:01951-1SUSE-SU-2025:01964-1

Timeline

  1. 09-05-2025
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: 9p/net: fix improper handling of bogus negative read/write replies In p9_client_write() and p9_client_read_once(), if the server incorrectly replies with success but a negative write/read count then we would consider written (negative) <= rsize (positive) because both variables were signed. Make variables unsigned to avoid this problem. The reproducer linked below now fails with the following error instead of a null pointer deref: 9pnet: bogus RWRITE count (4294967295 > 3)

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.72%

Chance of exploitation in the next 30 days

Percentile

54%

Versus all other CVEs

30-day change

Increase +0.03 pp

From 0.69% 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: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu141 products
  • linuxAll versions (No fix recorded) | < 6.8.0-100.100
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 6.8.0-1046.49
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian2 products
Linux2 products
  • linux≥ 070b3656cf228eaaef7b28b59264c5c7cdbdd0fb, < 468ff4a7c61fb811c596a7c44b6a5455e40fd12b | ≥ 070b3656cf228eaaef7b28b59264c5c7cdbdd0fb, < a68768e280b7d0c967ea509e791bb9b90adc94a5 | ≥ 070b3656cf228eaaef7b28b59264c5c7cdbdd0fb, < c548f95688e2b5ae0e2ae43d53cf717156c7d034 | ≥ 070b3656cf228eaaef7b28b59264c5c7cdbdd0fb, < 374e4cd75617c8c2552f562f39dd989583f5c330 | ≥ 070b3656cf228eaaef7b28b59264c5c7cdbdd0fb, < d0259a856afca31d699b706ed5e2adf11086c73b | 4.1
  • linux_kernel< 6.1.136 | ≥ 6.2, < 6.6.89 | ≥ 6.7, < 6.12.26 | ≥ 6.13, < 6.14.5

3 vendors · 145 products

References

30 links
Show all 30 references